Objective To investigate the levels of antibody against Japanese encephalitis (JE) in healthy population in Changping district, Beijing, China, and to find out the hidden troubles of people with weak immunity and epidemic spreading, thus providing a scientific basis for formulating strategies and measures to control JE. Methods A simple random sampling method was performed to collect residents' committees of 10 villages in Changping district in 2017. A total of 360 people from 10 age groups who lived in the local area for more than 6 months were selected as research subjects. Questionnaires were used to collect demographic features, JE vaccine immunization history, disease history of JE, and other information of these research subjects. Venous blood was collected, and serum JE IgG antibody was determined by plaque reduction neutralization test. The positive rates of antibodies of each group were determined by the chi-square test. Results The positive rate of JE antibody in healthy people was 93.61% in Changping district. There was a significant difference in the positive rate of antibodies between different age groups (χ²=27.053, P<0.05). There were no significant differences in the positive rates of JE antibody between different sexes, household registers, and people with immune history inoculated with different doses of live attenuated JE vaccine (χ²=0.215, 1.283, P>0.05). There was a significant difference in the positive rate of antibody between people at <1, 1-5, and 6-12 years after being inoculated with live attenuated JE vaccine (χ²=7.220, P<0.05). Conclusion The positive rate of antibody against JE in healthy population is at a high level in Changping district. It is necessary to strengthen the prevention and control of JE in children under 1 year old and young adults.