OBJECTIVE:To explore the influential factors for plasma concentration of paliperidone palmitate injection for pa-tients with schizophrenia. METHODS:37 schizophrenia patients who used Paliperidone palmitate injection and took plasma concentra-tion monitoring in Wuxi Mental Health Center from Sept. 2012 to Jun. 2015 was selected,the results were statistically analyzed,and the influential factors were preliminary explored. RESULTS:Totally 37 times were conducted for the plasma concentration monitoring for paliperidone with the average plasma concentration of(17.72±13.46)ng/ml,and 24 times(accounting for 64.86%)in the range of(10-60 ng/ml);the average plasma concentration of male patients was lower than that of female patients,the difference was statisti-cally significant(P<0.05);there was no significant difference in the average plasma concentration among different ages(P>0.05);there was also no significant difference in plasma concentration/dose ratio in patients with different daily dose(P>0.05);the average plasma concentration of patients with combination treatment was higher than that of single drug,the difference was statistically signifi-cant(P<0.05);and there was no significant difference in the average plasma concentration of relieved patients and ineffective treat-ment patients(P>0.05). CONCLUSIONS:The plasma concentration of paliperidone palmitate is affected by age,combination treat-ment and other factors,clinic can optimize the therapeutic regimen based on monitoring results of plasma concentration and patients’ symptoms to promote the rational drug use.