This study is an objective research to verify causality between social worker's social capital and OCB in Jeon-nam province including Kwangjoo. Survey was done directly from 255 social workers working in social welfare facilities. Study methodology was the structural equation to verify the influence of social capital on organized citizens' activities and the mediator effect of job satisfaction and organizational commitment. Using Fornell and Locker's two-step approach, this study verified the similarity between direct effectiveness and indirect effectiveness through bootstrap. I hope that the result of this study will be used as objective and academic material for social workers who work hard with sense of duty at field and expect that there will be a intensive follow-up research which can make social workers' social capital and make it stronger.