The influence of mixed-sex hospitalization of the patients with schizophrenia on the outcome of the illness was explored. The experimental group was consisted of 51 schizophrehics (33 males and 18 females) in the same mental ward, and the control group of 58 schizophrenics (28 males and 30 females) who were in male or female ward separately. All the patients were assessed and compared with Nurses' Observation Scale for Inpatient Evaluation (NOSIE) in the 3rd and 21st day after admission respectively. The scores of social ability and interest factors of experimental group (NOSIE) were increased more than control group, while the scores of psychiatric behaviour factor and total negative factor were decreased much more than control group. The male's increased scores of experimental group (NOSIE) in social ability factor were higher than control group, and meanwhile the female's decreased scores in psychiatric behaviour factor were lower than control group. Mixed-sex hospitalization of the patients with schizophrenia could not result in the deterioration of illness and was helpful for improving the social function.