Aim: To describe the epidemiological characteristics of Japanese encephalitis in Thai Binh province from 2009 to 2013. Subjects and Methods: All cases of Japanese encephalitis / encephalitis virus under investigation, kept at the center of Thai Binh Preventive Medicine, Medical Center of districts and cities in 2009-2013. A cross sectional survey and analysis of epidemiological factors such as age, sex, season, month, geographical area of all patients are diagnosed with Japanese encephalitis in Thai Binh province for 5 years from 2009 to 2013. Result: The percentage of positive test cas is 36/732 (accounting for 4.92 percent). The average incidence of Japanese encephalitis / 100.000 people in 5 years in Thai Binh province was 0.4 / 100.000 population. Mortality / 100.000 due to Japanese encephalitis in Thai Binh province is O. 1. The incidence rate of Japanese encephalitis is highest in summer from April to Jun. Conclusion: The average incidence of Japanese encephalitis annually from 2009-2013 was 0.4 / 100.000 population. The disease occurs in all districts, town in the province. The disease occurs seasonally in April and appeared in the highest increase in June. Japanese encephalitis diseases usually occur in children under 15, the highest in the group of 10-14 years old.