Objectives: ：This study was designed to investigate the correlation between defense mechanism and posttraumatic stress disorder in burn patients. Methods: ：We recruit 40 burn patients and we evaluate sociodemographic characteristics, characteristics related to burn, korean version of Impact of Event Scale-Revised (IES-R), Korean Version of Center for epidemiologic studies depression scale (CES-D) and Ewha Defense Mechanisms Test (EDMT). Multiple regression analysis was performed to evaluate the correlation between EDMT score and IES-R score. Results: ：Factor 2 of EDMT which consists of Ego-expansion subjects was significantly correlate with IER-S score. In factor 2, Controlling (β=-0.299, p<0.05), Sublimation (β=-0.276, p<0.05) is significantly correlate with IER-S score. Conclusions ：Some subjects of defense mechanism was significantly correlate with IES-R score. it might behelpful to understand defense mechanism for the posttraumatic stress disorder in burn patients.