Objective: To explore the characteristic and relation between personality, social support and ego identity development of the reform schools students. Methods: 279 and 361 students from the reform schools and normal schools are investigated by the Adolescents Ego Identity Status, SSQ and NEO-FFI. Results: Compared with the normal schools students, the reform schools students show higher diffusion status factor scores and remarkably lower delayed status factor scores; to the reform schools students, their subjective support and availability of support is related to extraversion, agreeableness, conscientiousness and neuroticism of their personality and the ego identity diffusion status and state. Conclusion: Social support plays an intermediary role in personality, ego identity diffusion and delayed status of the reform schools students.