Objective:To investigate the characteristics of implicit memory and its related factors in schizophrenic patients with negative and positive symptoms.Methods:Ninety-three schizophrenic patients (including 52 cases of negative symptoms group and 41 cases of positive symptoms group) and 30 normal controls (normal group) were tested with the method of Chinese character word completion method. The reaction time and correct rate were recorded and compared with analysis of variance and t-test, and the correlation with demographic factors was analyzed with Pearson correlation analysis. Results:Accuracy of implicit memory test in schizophrenia group: there were statistically significant differences in the accuracy of patients with different course of disease (≤5 years: (38±5)%, 5-15 years: (34±8)%, ≥15 years: (34±7)%, P<0.05).The differences were statistically significant in the accuracy of patients with different education levels(primary school: (35±6)%, junior and senior high school: (34±7)%, secondary college education and above: (39±5)%, P<0.05).The accuracy of patients with education years < 10 years ((34±7)%) was significantly lower than those with education years ≥10 years ((37±6)%, P<0.05).Reaction time results of implicit memory test in schizophrenia group : there were significant differences in reaction time of patients with different disease course(≤5 years: (3 248±971)ms, 5-15 years: (3 515±672)ms, ≥15 years: (3 925±842)ms, P<0.05).The differences were statistically significant in the reaction time of workers ((3 495±712)ms), farmers ((3 870±878)ms) and soldiers ((3 024±924)ms, P<0.05).The reaction time of patients with clozapine ((3 869±871)ms) was significantly higher than that of patients with olanzapine ((3 393±626)ms, P<0.05).Intergroup results of accuracy: the accuracy of normal control group ((40±5)%) was significantly higher than that of negative symptom group ((33±7)%, P<0.01).The accuracy of negative symptom group was significantly lower than that of positive symptom group ((37±6)%, P<0.01).Intergroup reaction time results: the reaction time of normal control group ((2 660±667)ms) was significantly lower than that of negative symptom group ((3 678±951)ms, P<0.01) and positive symptom group ((3 072±865)ms, P<0.05).The reaction time of negative symptom group ((3 678±951)ms)was significantly higher than that of positive symptom group( P<0.01).There was significant negative correlation between the accuracy of implicit memory and the course of disease in schizophrenia ( r=-0.22, P<0.05). Conclusion:The implicit memory of schizophrenic patients is related to the course of disease, taking drugs, and occupation.There may have differences in implicit memory between patients with negative and positive symptoms of schizophrenia.