Abstract: The aim of this research is to explore the relation between perceived security and PTSD of the earthquake victims one month after the disaster.About one month after Wenchuan earthquake, the investigators had gone to the resettlements of victims in Deyang, Mianzhu and Shifang cities of Sichuan Province, offered psychological assistance to victims and made this research.Questionnaire was consisted of two parts: Perceived Security Questionnaire for Earthquake Victims, and PTSD self-rating scale (PTSD Checklist Civilian version, PCL). The result displayed that there was a significant difference among the three factors of perceived security, and on the dimension of security needs,there was also a significant difference among age stages.Furthermore,multiple regression analysis showed that the regression coefficient of perceived security and PTSD is considerable.The finding of this study gives evidence to the importance of restoration of victims’ perceived security in post-disaster psychological assistance

Key words: perceived security, PTSD, security needs, ascription needs, certainty in control