In this paper, contents and successful experience of social security system of Taiwan are analyzed. The social security system of Taiwan is equipped with effective resource allocation, wide coverage, and relatively complete legislation, etc. However, there are still problems, such as heavy financial burden of the government, unsound social security system, etc. It also pointed out that Chinese mainland is confronted by low social security coverage, limited guarantee level and unsound legislation systems, etc. at present. It suggests that Chinese mainland shall perfect the social security system construction by referring to the experience of Taiwan completely, giving full play to the redistribution of social security income, increasing the input and improving the legislative work.