Objective: To study the influence of occupational environment on mental health of nurses. Methods: 671 registered nurses were surveyed with Symptom Checklist 90 (SCL-90).The related factors of positive symptoms were analyzed. Results: The nurses showed significantly higher positive item number and scores of somatization and hostility than those of the Chinese female norms. There were significant difference in the score of SCL-90 among the different department nurses; and the nurses who worked in the emergency and obstetric and gynecologic departments had higher score of SCL-90. The analysis of Logistic regression showed that occupational environment had influence on mental health and short nursing experence were related to some positive symptoms. Conclusion: There were some mental problems in the nurse sample and the nurse who worked in different occupational environments had different level of psychological health.