Abstract: Objective To understand the epidemic level and influencing factors of hepatitis B virus (HBV) in people aged 1-59 years in Dali Bai Autonomous prefecture, and provide evidences for prevention and control of HBV. Methods The stratified cluster sampling and random number table were used to enrolled subjects and a questionnaire survey was conduct to 3 622 local people aged 1-59 years in Dali Bai Autonomous prefecture and their blood samples were collected from May to June in 2018. Hepatitis B virus serological markers were tested by enzyme linked immunosorbent assay and influencing factors of HBV infection were determined by logistic regression model. Results The infection rate of HBV was 19.69%, and the positive rate of HBV surface antigen (HBsAg), HBV surface antibody (HBsAb) and HBV core antibody (HBcAb) was 1.13%, 52.76% and 19.57%, respectively. Seven kinds of serological markers patterns were observed, and the major type was immune pattern, which accounted for 52.74%. The HBV infection patterns showed significant difference between different sex, nation, age and HepB immune history (all P<0.001). Logistic models showed that younger age was a main protective factor and no immunization was the risk factor of HBV infection. Conclusion The HBV among people aged 1-59 years in Dali Bai Autonomous prefecture is at a low epidemic level, with immune patterns as the major epidemic pattern.