Objective To understand the relationship between the psychological health status and life events in middle school students in Chongqing urban and rural development pilot areas. Methods A total of 951 middle school students in Chongqing urban and rural development experimental areas were extracted using stratified random chester sampling method. Symptom Checklist（ SCL-90） and Adolescent Self-Rating Life Events Check-list（ ASLEC） were applied to evaluate the research objects’ psychological status and the difference among different genders and ages， so as to analysis the factors influencing the results of SCL-90. Results Totally 612 middle school students were detected positive， accounting for 64.30% of the whole estimated. Mental problems often arose in middle school students included compulsion， interpersonal sensitivity， depression， anxiety， hostility， paranoia and so on. Each factor score in SCL-90 of middle school girls were higher than those of boys （P＜ 0.05）. Compared with those who were less than 16 years old students， the scores of obsessive-compulsive， interpersonal sensitivity， depression and psychosis in SCL-90 in middle school students who were 16 years and older were higher， the difference was statistically significant（ P＜ 0.05）. Each factor score of ASLEC in SCL- 90 screening positive middle school students was higher than that in SCL-90 screening negative students， and the difference was significant（ P ＜ 0.01）. Stepwise regression analysis indicated that the top two main factors affecting middle school students’ SCL-90 scores in urban and rural development experimental areas sorted by regression contribution were ASLEC total scores and ASLEC penalty scores. Conclusions Middle school students’ mental health status in Chongqing urban and rural development experimental areas cannot be ignored， and negative life events have a predictable impact on middle school students’ mental health status