Objective To analyze the epidemiological characteristics of legal infectious diseases in Changfeng County from 2016 to 2020 and to understand the major diseases affecting the prevalence level of infectious diseases,so as to target the prevention and control of infectious diseases. Methods The data were obtained from the legal infectious disease surveillance data of Changfeng County in the "China Disease Surveillance Information Reporting Management System - Infectious Disease Surveillance System" from 2016 to 2020.The data obtained were used to analyze the prevalence of legal infectious diseases in Changfeng County in recent 5 years.Moreover,the prevention and control effect of the vaccine against infectious diseases was evaluated in conjunction with vaccination data. Results In 2016—2020,23 230 cases of legal infectious diseases were reported in Changfeng County,with an annual incidence rate of 598.73/100 000.The incidence rate of legal infectious diseases showed an increasing trend year by year (χ²_trend = 75.944,P＜0.001).The main diseases affecting the incidence of infectious diseases were other infectious diarrhea,hand-foot-mouth disease,hepatitis B,tuberculosis,and syphilis.The incidence of male was more than that of women,and the incidence rate was statistically significant (χ²= 699.123,P< 0.001).The incidence in urban areas was significantly higher than that in rural areas.The incidence was distinctly seasonal.The vaccine incidence rate for infectious diseases has been kept at a low level. Conclusion The overall incidence level of legal infectious diseases in Changfeng County has increased in recent 5 years,with occasional outbreaks.Vaccination plays an important role in controlling the prevalence of infectious diseases.