Objective To investigate the influencing factors for achieving sustained virological response( SVR) to pegylated interferon alpha-2a combined with ribavirin in Uygur and Han patients with chronic hepatitis C,and to provide a reference for predicting the treatment of chronic hepatitis C in Uygur and Han patients. Methods A retrospective analysis was performed on the clinical data of 160 patients( 80 cases of Uygur nationality and 80 cases of Han nationality) with chronic hepatitis C who received pegylated interferon alpha-2a combined with ribavirin in the Infectious Disease Hospital in Hetian from January 2012 to March 2014. All patients were followed up for 24 weeks after48 weeks of treatment. The two groups were compared in terms of the ratios of rapid virological response( RVR),early virological response( EVR),end treated virus response( ETVR),SVR,and no response( NR). The factors which might influence achieving SVR to interferon therapy in the two groups were subjected to univariate analysis and multivariate analysis( conditional logistic regression). For normally distributed continuous data,the comparison was made by t test,and Wilcoxon rank-sum test was made for abnormally distributed continuous data. The comparison of categorical data was made by chi-square test. And univariate analysis and multivariate analysis( conditional logistic regression) were carried out. Results There were no significant differences in the rates of RVR( 48. 8% vs 60. 0%,P > 0. 05),EVR( 53. 8% vs 63. 8%,P > 0. 05),ETVR( 72. 5% vs 78. 7%,P > 0. 05),SVR( 63. 8% vs 72. 5%,P > 0. 05),and NR( 27. 5% vs21. 3%,P > 0. 05) between Uygur group and Han group. The univariate analysis showed that age and age > 40 years were the influencing factors for all patients' SVR( P < 0. 05). Age > 40 years and HCV RNA level > 1 × 106 copies / ml were the influencing factors for Uygur patients' SVR( P < 0. 05). Male sex,age,and age > 50 years were the influencing factors for Han patients' SVR( P < 0. 05). Multivariate analysis showed that age > 40 years and HCV RNA level > 1 × 106 copies / ml were the influencing factors for Uygur patients. And age > 50 years and male sex were the influencing factors for Han patients. Conclusion There is no significant difference in clinical efficacy of pegylated interferon alpha-2a combined with ribavirin in the treatment of chronic hepatitis C between Uygur patients and Han patients. Age > 40 years and HCV RNA level > 1 × 106 copies / ml go against achieving SVR for Uygur patients. Age > 50 years and male sex go against achieving SVR for Han patients.