Objective To explore the epidemic trend and influencing factors of hepatitis C among people who donate blood without compensation in Inner Mongolia.Methods Retrospectively analyzed the relevant data of 1860 unpaid blood donors in Inner Mongolia from January 2016 to December 2020.The data was from the China Information System for Disease Control and Prevention,and the data of unpaid blood donation population was from the Big Data of Public Opinion on Unpaid Blood Donations in My Country.According to hepatitis C infection,they were divided into infected group(324 cases)and uninfected group(1536 cases).The prevalence rate of hepatitis C and the influencing factors of hepatitis C complication in non-remunerated blood donors were analyzed.Results In 2020,the prevalence of hepatitis C was the highest among unpaid blood donors,which was 6.45%,followed by 2019(4.62%),2018(3.60%),2017(2.10%)and 2016(0.65%).There was statistically significant difference in the prevalence of hepatitis C in different years(P＜0.05).Univariate analysis showed that there were differences between the two groups in family history of hepatitis disease,history of hospitalization,history of sharing glass syringes,history of sharing razors,and history of blood transfusion(P＜0.05).Multivariate Logistic regression analysis showed that family history of hepatitis disease,history of hospitalization,history of using glass syringes,history of sharing razors,and history of blood transfusion were risk factors for hepatitis C complication in unpaid blood donors(P＜0.05).Conclusion From 2016 to 2020,the non-remunerated blood donors in Inner Mongolia who have a family history of hepatitis disease,hospitalization,sharing of glass syringes,sharing of razors and blood transfusions have a higher possibility of hepatitis C infection,and attention should be paid to these risk factors.