Objective To investigate the effects of folic acid on elderly patients with chronic schizophrenia. Methods A total of 100 cases of elderly patients with chronic schizophrenia were divided into control group and study group by random number table method. Patients in the study group were given oral intervention of 10 mg/d folic acid. The results of hemoglobin， red blood cell count， blood homocysteine （Hcy）， folic acid level and Mini-mental State Examination（ MMSE） and Wisconsin Card Sorting Test（ WCST） were compared and analyzed before and after treatment. Results After folic acid intervention， compared with the control group， the level of folic acid in the study group increased， the Hcy level decreased， while the hemoglobin and red blood cell count increased. And the differences were statistically significant compared with those before treatment（ P＜0.05）. After treatment， the score of negative scale decreased and the number of completed classifications increased in the study group. The difference between the control group and the treatment group was statistically significant， but the difference of MMSE score was not statistically significant. Conclusions Folic acid adjuvant therapy for elderly patients with chronic schizophrenia can improve the physical symptoms such as anemia， and also can improve the negative symptoms and cognitive symptoms of patients to a certain extent.