Objective To explore the influencing factor of duration of untreated psychosis(DUP) and the relationship between duration of untreated psychosis and treatment outcome in epidemiological first-episode schizophrenia. Methods 912 medical records of the first episode schizophrenia patients were recruited in the study for epidemiological survey . The general medical data, clinical diagnosis, and treatment outcome were collected. DUP was determined refer to symptom onset for schizophrenia (SOS) scale. Patients were divided into short DUP and long DUP groups according to the median values of DUP values. Results Between short DUP and long DUP groups, the difference in marriage was significant ( P < 0. 05). The unmarried patients in the short DUP group (63.7% ) was higher than the long DUP group (52.6% ), the variance was significant (λ2 =5.990, P<0.05). The divorce in the short DUP group (0.6% ) was lower than the long DUP group (4.4% ) , the variance was significant (λ2 =5.079, P<0.01).The simple schizophrenia in the short DUP group (1.5%) was lower than the long DUP group (4. 1% ) , the variance was significant (λ2 =5.868, P<0.05). The treatment outcomes between the two groups had a significant variance ( λ2 =36.093, P < 0.01) , and the Ridit analysis of treatment outcomes between the two groups showed significant difference ( u = 5.183, P<0.01). The marriage,age of onset and clinical diagnosis were significantly correlated with DUP in multiple factor Logistic regression analysis. Conclusion The marriage,age of onset and clinical diagnosis are significantly correlated with DUP in the first episode schizophrenia patients,the longer of DUP and the worse of treatment outcome.