The research aims to examine and analyze the influence of organizational climate and personality on job stress and its impact on organizational citizenship behavior. This study uses all employees Clinical Lab. Prodia branch Menteng is using saturated sample in order to obtain a sample of 50 employees. The approach that is used in this research is Structural Equation Model (SEM) based on Partial Least Square (PLS). Results show that the organizational climate provides a positive and significant effect on the behavior of citizenship. Then the organizational climate does not give effect to job stress. Then type A personality has significant impact on job stress while type B personality does not have a significant impact on job stress. Type A personality does not have a significant impact on organizational citizenship behavior, while personality type B does not have a significant impact on the organizational citizenship behavior. And the last job stress does not influence the organizational citizenship behavior.