一个是实例 一个是指针 大小不一样感觉很正常。
不过确实2个的时候有问题
[view@localhost c]$cat ss.c
#include<stdio.h>
typedef struct man{
        char name[10];
        int age;
        char phone[12];
}* pMAN;

int main(){
    pMAN a=(pMAN)malloc(sizeof(pMAN)), b = (pMAN)malloc(sizeof(pMAN));
    strcpy(a->name,"hwt");
    a->age=34;
    strcpy(a->phone,"18677151934");
    strcpy(b->name,"hwt");
    b->age=34;
    strcpy(b->phone,"18677151934");
    printf("a man named %s's age is %d,and phone is %s\n",a->name,a->age,a->phone);
    printf("a man named %s's age is %d,and phone is %s\n",b->name,b->age,b->phone);
    exit(0);
}
[view@localhost c]$cc -o ss ss.c
[view@localhost c]$./ss
a man named hwt's age is 34,and phone is hwt
a man named hwt's age is 34,and phone is 18677151934

你还不明白呀，当然会有问题啦，你给这个指针分配的空间就不够，他当然会跟其他变量的空间重叠啦~

谢谢  明白了