In order for Korean coast guard to restore trust of the Korean people through outstanding performance, constituents of organization need to develop and promote social capital. This study verifies what kind of influence social capital has on perceptions of organizational effectiveness. Results of this study is, first, Korean coast guard showed having high level of social capital. This can be attributed to efforts to promote the perception of building trust between colleagues and establish it as a cultural elemenet. Second, perception of organizational performance differs by rank, education and gender. This can be due to differences in work, work environment and system between ordinary police and coast guard. Third, results showed increase in social capital lead to increase in perception of organizational performance. This means social capital induces change in personal perception by sharing information and interests, contributing to oganizational performance. Fourth, stressed was tested as a moderating variable of social capital and perception of organizational performance. Results showed no moderating effect. Based on the findings of this study, in order to promote perception of performance of Korean coast guard, the need for establishment of social capital should be recognized. coast guard management, in terms of organizational management, needs to develop trust, participation and network of the constituents of Korean coast guard. For this to happen, organizational culture of maximizing input from constituents when improving environment and determining policies should be developed.