diff --git a/C++/204 Count Primes.cpp b/C++/204 Count Primes.cpp
new file mode 100644
index 0000000..041cfed
--- /dev/null
+++ b/C++/204 Count Primes.cpp	
@@ -0,0 +1,21 @@
+class Solution {
+public:
+    int countPrimes(int n) {
+        int count=0;
+        if(n<=1)   return 0;
+
+        vector<bool> prime(n,true);
+        prime[1]=false;
+        for(int i=2;i<n;i++)
+        {
+            if(prime[i])
+            {
+                count++;
+                for(int j=i;j<n;j+=i){
+                    prime[j]=false;}
+            }
+        }
+        return count;
+
+    }
+};