A Study on the Background of Implementation of Public Assistance This study analyses features in implementation which are corresponding to the background including ideological inclination, political context, and administrative basis of public assistance. The purpose of this research is to provide intelligence to consider in the way of developing new implementation model for public assistance in Korea. After welfare reform in 1996, TANF replace AFDC as a main public assistance in the U.S. This study is a case study of TANF, because implementation and the background of TANF cover so many aspects of debates about poverty and public assistance. This analysis showed ideological background including new liberalism, new conservatism, paternalism and new federalism committee occupied by Republicans have had an effect on the contents and implementation of TANF. Devolution, privatization, closer relationship between welfare, workforce development agencies, performance measures, performance based contracting, complicated application process, enhanced case management, computerization, and all features have been caused by ideological and politicalbackgrounds of TANF. Furthermore, these features have infringed the right for the public assistance of citizen. In Korea, a lot of political efforts have done to improve the implementation of public assistance. But every effort was made without consideration in the context of public assistance. In case, case management is selected as a important tool for the implementation of public assistance, corresponding between goal of the policy and the tool should be assured.