The university years are generally viewed as a time of major psychosocial growth. According to E. H. Erikson's psychosocial theory, the personality component that is most likely to be the focus of such growth is ego identity. Based on Eriksonian position James Marcia developed some techniques to measure college students' identity status in which four categories were identified. The purpose of this study is to test the validity of Marcia's categorization system in Chinese university environment. An identity status questionnaire concerning occupational and self-certainty was conducted with 1117 students (578 males, 539 females, 273 freshmen, 280 sophomors, 278 juniors, 286 seninrs) from two universities in Taipei. The results of the study indicated: (1) The proportions of different identity status were that 26.3% were identity achievers, 16.6% were foreclosues, 44.3% were moratoriums, and 12.6% were identity diffusions. (2) significant increase in the frequency of students in the identity achievement status with the increase from freshman to senior years. (3) There were more identity achievers in the student group who had work experiences. (4) The students who had higher academic status tend to be more identity achievers. (5)The students who participated student's organizations tend to de more identity achievers. The problems concerning the methodology for furture reserch were discussed.