BACKGROUND: With the rapid development of modern society, psychological problems in college students have been paid high attention by educatienal organizations of psychological health in China. OBJECTIVE: To probe into the influencing factors of psychological problems in college students. DESIGH: Cluster sampling 1∶2 paired observation, case-control study. SETTING: Medical College of Wuhan Polytechnic University. PARTICTPANTS: 1 200 sophomores with the age ranged 19-20 years were selected from Wuhan Polytecnic University by cluster sampling at June 2001, and 145 students with the scores of more than 3 factors greater than 3 points were screened by Symptom Checklist 90 (SCL-90) (including 9 factors of somatization, compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobia, paranoid and schizophrenia. The higher the grade was, the severer the symptom was) to be the psychological problem group. Subjects were selected to be the normal controls at the ratio of 1∶2 with those in the psychological problem group, whose classes, specialties and ages (the difference was less than 2 years) were similar to those of the enrolled patients. 290 students normal in the indexes of SCL-90 were taken as the matched group. Of all subjects in both experiment groups, there were 173 males and 262 females with an average age of 19.2 years. METHODS: ① The subjects in the two experiment groups were investigated of the psychological health by SCL-90 as well as the personality characteristics and Eysenck Personality Questionnaire (EPQ) (For Adult). The EPQ statistic software designed by the Institute for Juvenile and Children, Tongji Medical College of Huazhong University of Science and Technology was adopted to acquire the E score (introversion, extroversion), N score (nervousness), P score (psychoticism), L score (conceal) and quantity form quadrant of E-N coordinate picture, so as to define the tendencies of characters. ② The psychological problem was considered to be the dependent variable, while all relevant factors (The influencing factors of psychological problem included the understanding from parents, relationship with family members, desire for learning, personality characteristics, over-high P score, over-high/low E score, over-high/low N score) were taken as the independent variable. Single-factor Logistic regression analysis was conducted at 1:2. ③ Based on 1:2 single-factor Logistic regression analysis, the variances were selected from factors of P ＜ 0.01 together with the Logistic regression models of multifactor at 1:2 by stepwise regression method.MAIN OUTCOME MEASURES: ① Comparison in the SCL-90 score between the psychological problem group and the normai control group. ② Single-factor and multivariate analysis of the relevant factors of psychological problems. RESULTS: A total of 435 enrolled students were involved in the analysis of results. ① The average score of somatization, compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobia, paranoid and schizophrenia in students of the psychological problem group was higher than that in the normal control group (t=-13.39, 29.64, 27.09, 26.04, 19.52, 18.13, 14.15, 18.61, 22.41, P＜ 0.01). ② Nine factors were selected in the single factor analysis after the Logistic regression analysis, including 6 protective factors of understanding from parents, relationship with family members, desire for learning, personality characteristics, E ＞ 61.5, N ＜ 38.5, while he other 3 factors (P ＞ 61.5, E ＜ 38.5, N ＞ 61.5) were risk factors. The multivariate analysis showed that factors of relationship with family members, desire for learning as well as personality characteristics were protective factors, while it was a risk factor when N ＞ 61.5.CONCLUSION: The psychological problems in college students relate to the relationship with family members,understanding from the parents, desire for learning as well as the character trait and personality characteristics.