Objectives: To investigate and compare elderly survivors’ mental health in different time before and after Wenchuan earthquake, to assess the impact of earthquake on mental health and related factors. Methods: Chinese Mental Health Inventory for the elderly and Impact of Event Scale-Revised (IES-R) was used to measure the mental health and post-traumatic stress disorder; Trauma exposure scale, Social Support Rating Scale (SSRS), Simplified Coping Style Questionnaire (SCSQ), and Social Axioms were used to assess possible predictors. Results: The prevalence of PTSD was 30.8%, 17.2%, and 20.3%, four months, ten months, and two years after the Earthquake respectively. Its predictors were trauma exposure and negative coping strategies. Elderly survivors’ mental health after the earthquake (M6m=493.78，M10m=482.07，M2y=480.33) were significantly worse than that of 4 months before earthquake (M=531.47) after controlling demographics. In hierarchical regression analyses, mental health was positively associated with subjective social support (Beta = 0.45), positive coping strategies (Beta = 0.24), and education level (Beta = 0.18), and negatively associated with negative coping strategies (Beta = -0.22). Buddhism belief didn’t have an impact on mental health. Elderly survivors’ social belief changed after earthquake and associated with mental health. The score of social complexity, reward for application, and fate control of older adults in disaster areas was higher than control sample, t1(452)=5.25(p<0.001), t2(452)=5.37(p<0.001), t3(452)=2.61(p=0.009). Conclusions: The prevalence of PTSD was high 6 months after earthquake, but decreased in follow-up study. Elderly survivors’ mental health adults was impacted significantly during the Earthquake, didn’t recover in two years. The mental health was positively related with social axiom, but negatively related with negative coping strategies and fate control.