The purpose of this paper is to analyze the contribution of the local government’s policy experiments to the development of community welfare, focusing on the political efficacy of local governments: When attempting innovative policy experiments, the cost of failure is small while the ripple effect is large. In particular, from the perspective of ‘cost-efficient innovation’, this paper analyzes the mechanism of local government’s welfare politics (i.e. policy experiments of local governments → improving efficiency and effectiveness of community welfare → local social innovation → enhancing citizens’ quality of life). Through these analyses, this paper argues that the welfare politics of Local Autonomous Entity, including local governments, should be activated in order to continuously develop South Korea’s community welfare. This is because it is politics that can change a series of systems and culture that surround us. This paper is divided into three parts. First, a review on the basics needed to politically understand South Korea’s community welfare. Second, an exploration on how the local government’s ‘innovative policy experiments’ are developing community welfare. Third, an emphasis on the significance of politics in the development of community welfare, and some suggestions for vitalizing the welfare politics of local governments in South Korea.