diff --git a/backends-velox/src-delta/test/scala/org/apache/gluten/execution/VeloxDeltaParquetRowGroupSuite.scala b/backends-velox/src-delta/test/scala/org/apache/gluten/execution/VeloxDeltaParquetRowGroupSuite.scala
new file mode 100644
index 00000000000..7fa4a85e98b
--- /dev/null
+++ b/backends-velox/src-delta/test/scala/org/apache/gluten/execution/VeloxDeltaParquetRowGroupSuite.scala
@@ -0,0 +1,113 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.gluten.execution
+
+import org.apache.gluten.config.GlutenConfig
+
+import org.apache.spark.SparkConf
+
+import org.apache.hadoop.fs.Path
+import org.apache.parquet.hadoop.ParquetFileReader
+import org.apache.parquet.hadoop.util.HadoopInputFile
+
+import java.io.File
+
+/**
+ * Reproduction for the Parquet row-group sizing bug behind Delta's
+ * `DeletionVectorsWithPredicatePushdownSuite` abort.
+ *
+ * That suite sets `parquet.block.size = 2MB` on `spark.sparkContext.hadoopConfiguration`, writes a
+ * 1M-row Delta table, and asserts the resulting data file has more than one row group. Under Gluten
+ * the data file has a single row group, so `beforeAll` throws and the whole suite aborts.
+ *
+ * VeloxParquetRowGroupSuite already showed that a *plain* Parquet write (`INSERT OVERWRITE
+ * DIRECTORY ... USING PARQUET`) DOES honor `parquet.block.size` from that same runtime Hadoop conf
+ * (multiple row groups). These tests isolate the remaining difference -- the *Delta* write path --
+ * using the same conf source and data. They assert the desired behavior (> 1 row group) and are
+ * expected to FAIL today, reproducing the Delta abort; they should turn green once the Hadoop-conf
+ * block size is plumbed through the Delta write path to the native writer. The deletion-vectors
+ * variant matches the original suite (which enables DVs on the table); the initial write is
+ * identical with or without DVs, so both cases pin down the write path rather than DVs or
+ * checkpoints.
+ */
+class VeloxDeltaParquetRowGroupSuite extends DeltaSuite {
+
+  override protected def sparkConf: SparkConf =
+    super.sparkConf.set(GlutenConfig.NATIVE_WRITER_ENABLED.key, "true")
+
+  // ~8MB of int64 (uncompressed): far above the 1MB block size used here, so a writer that honors
+  // the block size produces several row groups.
+  private val numRows: Long = 1000000L
+  private val smallBlockSize: Long = 1L * 1024 * 1024 // 1MB
+
+  private def listParquetFiles(dir: File): Seq[File] = {
+    val entries = Option(dir.listFiles()).getOrElse(Array.empty[File])
+    entries.filter(f => f.isFile && f.getName.endsWith(".parquet")).toSeq ++
+      entries.filter(_.isDirectory).flatMap(listParquetFiles)
+  }
+
+  private def rowGroupCount(dir: File): Int = {
+    val parquetFiles = listParquetFiles(dir)
+    assert(parquetFiles.nonEmpty, s"no parquet file written under ${dir.getAbsolutePath}")
+    parquetFiles.map {
+      file =>
+        val in = HadoopInputFile
+          .fromPath(new Path(file.getAbsolutePath), spark.sessionState.newHadoopConf())
+        val reader = ParquetFileReader.open(in)
+        try {
+          reader.getFooter.getBlocks.size().toInt
+        } finally {
+          reader.close()
+        }
+    }.sum
+  }
+
+  private def writeDelta(path: String, enableDeletionVectors: Boolean): Unit = {
+    // scalastyle:off hadoopconfiguration
+    // Mirror Delta's `hadoopConf().set("parquet.block.size", ...)`, which resolves to exactly this
+    // conf object in DeletionVectorsWithPredicatePushdownSuite.
+    val hadoopConf = spark.sparkContext.hadoopConfiguration
+    // scalastyle:on hadoopconfiguration
+    hadoopConf.set("parquet.block.size", smallBlockSize.toString)
+    try {
+      val writer = spark.range(0, numRows, 1, 1).toDF("id").write.format("delta")
+      val withOptions =
+        if (enableDeletionVectors) writer.option("delta.enableDeletionVectors", "true") else writer
+      withOptions.save(path)
+    } finally {
+      hadoopConf.unset("parquet.block.size")
+    }
+  }
+
+  test("delta write should respect parquet.block.size set on the runtime Hadoop conf") {
+    withTempPath {
+      dir =>
+        writeDelta(dir.getCanonicalPath, enableDeletionVectors = false)
+        assert(rowGroupCount(dir) > 1)
+    }
+  }
+
+  test(
+    "delta write with deletion vectors should respect parquet.block.size on the runtime Hadoop " +
+      "conf") {
+    withTempPath {
+      dir =>
+        writeDelta(dir.getCanonicalPath, enableDeletionVectors = true)
+        assert(rowGroupCount(dir) > 1)
+    }
+  }
+}
diff --git a/backends-velox/src/test/scala/org/apache/spark/sql/execution/VeloxParquetRowGroupSuite.scala b/backends-velox/src/test/scala/org/apache/spark/sql/execution/VeloxParquetRowGroupSuite.scala
new file mode 100644
index 00000000000..37d6d25d318
--- /dev/null
+++ b/backends-velox/src/test/scala/org/apache/spark/sql/execution/VeloxParquetRowGroupSuite.scala
@@ -0,0 +1,124 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.spark.sql.execution
+
+import org.apache.gluten.config.GlutenConfig
+import org.apache.gluten.execution.VeloxWholeStageTransformerSuite
+
+import org.apache.spark.SparkConf
+import org.apache.spark.util.Utils
+
+import org.apache.hadoop.fs.Path
+import org.apache.parquet.hadoop.ParquetFileReader
+import org.apache.parquet.hadoop.util.HadoopInputFile
+
+import java.io.File
+
+/**
+ * Validates which configuration channel actually controls the Parquet row-group size of Gluten's
+ * native (Velox) writer.
+ *
+ * Background: Delta's `DeletionVectorsWithPredicatePushdownSuite.beforeAll` writes a 1M-row table
+ * with `hadoopConf().set("parquet.block.size", 2MB)` and asserts the resulting file has more than
+ * one Parquet row group. Under Gluten the file has a single row group, so `beforeAll` throws and
+ * the whole suite aborts. These tests pin down why: the native writer flushes a row group when the
+ * accumulated uncompressed size reaches `maxRowGroupBytes` (default 128MB, from
+ * `parquet.block.size`) or the row count reaches `maxRowGroupRows` (default 100M). ~8MB of `int64`
+ * data is far below the 128MB default (one row group) but far above the 1MB block size used here
+ * (several row groups). For a plain Parquet write the runtime Hadoop-conf block size DOES reach the
+ * native writer (all three tests below pass); the Delta abort is instead specific to the Delta
+ * write path and is reproduced in VeloxDeltaParquetRowGroupSuite.
+ */
+class VeloxParquetRowGroupSuite extends VeloxWholeStageTransformerSuite with WriteUtils {
+
+  override protected val resourcePath: String = ""
+  override protected val fileFormat: String = "parquet"
+
+  override protected def sparkConf: SparkConf =
+    super.sparkConf.set(GlutenConfig.NATIVE_WRITER_ENABLED.key, "true")
+
+  // ~8MB of int64 data: << the 128MB default block size, >> the 1MB block size used below.
+  private val numRows: Long = 1000000L
+  private val smallBlockSize: Long = 1L * 1024 * 1024 // 1MB
+  private val glutenBlockSizeKey = "spark.gluten.sql.columnar.parquet.write.blockSize"
+
+  private def rowGroupCount(dir: File): Int = {
+    val parquetFiles =
+      Option(dir.listFiles((_, name) => name.endsWith(".parquet"))).getOrElse(Array.empty[File])
+    assert(parquetFiles.nonEmpty, s"no parquet file written under ${dir.getAbsolutePath}")
+    parquetFiles.map {
+      file =>
+        val in = HadoopInputFile
+          .fromPath(new Path(file.getAbsolutePath), spark.sessionState.newHadoopConf())
+        Utils.tryWithResource(ParquetFileReader.open(in))(_.getFooter.getBlocks.size())
+    }.sum
+  }
+
+  // Writes `numRows` longs to `path` via the native Velox writer (checkNativeWrite asserts the plan
+  // actually offloads to ColumnarWriteFilesExec, so we are exercising the native writer).
+  private def writeRangeNatively(path: String): Unit = {
+    withTempView("velox_rowgroup_src") {
+      spark.range(0, numRows, 1, 1).toDF("id").createOrReplaceTempView("velox_rowgroup_src")
+      checkNativeWrite(
+        s"INSERT OVERWRITE DIRECTORY '$path' USING PARQUET SELECT * FROM velox_rowgroup_src")
+    }
+  }
+
+  test("native writer emits a single row group at the default (128MB) block size") {
+    withTempPath {
+      f =>
+        writeRangeNatively(f.getCanonicalPath)
+        // Exactly what DeletionVectorsWithPredicatePushdownSuite hits: ~8MB under the 128MB default
+        // is one row group, so its `> 1 row group` assert fails and the suite aborts.
+        assert(rowGroupCount(f) === 1)
+    }
+  }
+
+  test("native writer honors the Gluten block-size conf and emits multiple row groups") {
+    withTempPath {
+      f =>
+        withSQLConf(glutenBlockSizeKey -> smallBlockSize.toString) {
+          writeRangeNatively(f.getCanonicalPath)
+        }
+        // The Gluten conf is read directly by the native writer, so the 1MB block size takes effect
+        // and the file is split into several row groups.
+        assert(rowGroupCount(f) > 1)
+    }
+  }
+
+  // Control: a plain Parquet write DOES honor `parquet.block.size` set on the runtime Hadoop conf,
+  // so this passes (multiple row groups). The Delta `beforeAll` abort is therefore NOT a generic
+  // native-writer problem -- it is specific to the Delta write path, reproduced separately in
+  // VeloxDeltaParquetRowGroupSuite.
+  test("native writer should respect parquet.block.size set on the runtime Hadoop conf") {
+    // scalastyle:off hadoopconfiguration
+    withTempPath {
+      f =>
+        // Mirror Delta's `hadoopConf().set("parquet.block.size", ...)`: mutate the runtime Hadoop
+        // conf the write actually reads, rather than a session-creation `spark.hadoop.*` setting.
+        val hadoopConf = spark.sparkContext.hadoopConfiguration
+        hadoopConf.set("parquet.block.size", smallBlockSize.toString)
+        try {
+          writeRangeNatively(f.getCanonicalPath)
+        } finally {
+          hadoopConf.unset("parquet.block.size")
+        }
+        assert(rowGroupCount(f) > 1)
+    }
+    // scalastyle:on hadoopconfiguration
+  }
+}