diff --git a/2.判断素数.cpp b/2.判断素数.cpp
new file mode 100644
index 0000000..2af3b9b
--- /dev/null
+++ b/2.判断素数.cpp
@@ -0,0 +1,18 @@
+#include<stdio.h>
+int main()
+{
+ int a=0;//�ж�p�����Ӹ���
+ int p;
+ int i;
+ scanf("%d",&p);
+ for(i=2;i<p;i++)
+ {
+  if(p%i==0)
+   a++;
+ }
+ if(a==0)
+  printf("%d is a prime\n",p);
+ else
+  printf("%d is not a prime\n",p);
+ return 0;
+}