Abstract: Objective To understand the epidemiological characteristics of hepatitis B, evaluate the incidence of hepatitis B in Inner Mongolia from1991 to 2010 and provide evidence for the prevention and control of hepatitis B. Methods Statistical analysis was conducted on the incidence data of hepatitis B in Inner Mongolia during this period with Excel software. Results The incidence of hepatitis B began to increase year by year after 1995 and began to decline in 2008. The average annual incidence was 79.41/lakh and the highest incidence was 140.58/lakh. The disease mainly occurred sporadically without obvious seasonality and regionality. More cases occurred in males than in females. The cases in farmers accounted for the highest proportion, and the case number in people aged 15-54 years was highest, accounting for 81.52%. The incidence in age group of 0-4 years declined with year. Conclusion The increase of hepatitis B vaccination coverage had facilitated the reduction of the incidence of hepatitis B in people aged ＜15 years. It is necessary to conduct further study on hepatitis B vaccination strategy in floating population and in adults, increase hospitalized child birth rate and block mother to child transmission of HBV.