The purpose of this study is to identify the impact of perceived social safety on the life satisfaction among one-person households and to verify the mediated effects of social capital(social communication, solidarity, and inclusion) in the process. The subject were 1,283 people in one-person households out of the social survey data of Daejeon City in 2014, and the data were analyzed by multiple regression and 3-steps regression analysis of Baron & Kenny(1986) using the SPSS 21.0. Statistical significance of the intermediary route of social capital was verified by the Sobel Test. The analysis results are as follows: First, the higher the perceived social safety among one-person households, the higher the life satisfaction. Second, social capital(social communication, solidarity and inclusion) has a partial mediation effects in relationship between perceived social safety and life satisfaction among one-person households. In addition, to verify the statistical significance of social capital, the results of the Sobel Test show statistically significant and it has been verified that social capital has a mediated effect between perceived social safety and life satisfaction. These results show that in order to improve the life satisfaction among one-person households, it is necessary to consider and improve both perceived social safety and social capital.