Seen from the viewpoints of politics and administration, the retirement system of civil servant is related to the overall planning and flexible utilization of human resource, the improvement of national competitiveness and the collocation of financial resource of a country; seen from the viewpoint of economy, the prosperity or depression of national economy closely affects the planning of retirement payment system; in the aspect of society, as the aged society comes earlier than expected and the social structure changes, the retirement system of civil servant is related to whether the living security and social welfare system for the aged people is sound enough. Through the proper and reasonable retirement payment, the retirement system of civil servant is intended, firstly, to motivate the civil servants to be satisfied with the job and work hard for the public; secondly, to provide a reasonable income for the civil servants and guarantee their life in the years after retirement; and thirdly, with the reasonable retirement payment mechanism and the social security mechanism of the country, to construct a complete social security system network and build a safe and peaceful society in which all people can make their own livings. The implementation of the new pension system has really improved the problems faced in the old public finance-based pension system, and has laid a solid foundation in stabilizing the source of pension fund and establishing the civil servants' concept of being prepared to burden their post-retirement life when they are on the job. However, the current retirement system was designed more than 20 years ago and some tradeoff or progressive measures were taken for the purpose of reducing the resistance in the beginning of implementation. As the age and the environment both have changed, some provisions of the pension system have been behind the time. Therefore, it is really necessary to research how to manage and operate the retirement system, think over the problems in the current retirement system of civil servant, and research how to build a better retirement fund system and balance the retirement benefits of the civil servants of different generations. In this thesis, the legal system of retirement of civil servant is the subject of research and the other related administrative legal provisions are used for explanation, and the basic theories of administrative law ¡V administrative principles, administrative organization, administrative authority, administrative remedy, and administrative supervision, are used as the research methods to review the retirement system of civil servant in Taiwan. Through the research it is found that, the average age of Taiwanese people has been higher and a lot of civil servants choose to retire earlier for they can receive monthly pension for a long time; this is likely to deteriorate the governmental finance. How to solve this problem efficiently and reasonably, relieve the accumulation of retirement cost and avoid it from being transferred to the later generations as a heavy burden, maintain the existing rights and benefits, provide a reasonable guarantee for the original expectation of civil servants and distribute the national resources reasonably? It is necessary for us to think about for planning a reasonable legal system of retirement.