Abstract:The epidemic characteristics of the Japanese B encephalitis infection in Guangdong province was investigated by the methods of descriptive epidemiological and linear regression analysis.From 1990 up to present,there appeared two small peaks of out-breaks of Japanese B encephalitis infection during 1995 and 2003 respectively,while the incidence of this infection was rather low during other years.The main epidemic area localized in the east and west parts of Guangdong province and the epidemic season was between May and July with the peak time of out-break at June.The reported cases of patients with Japanese B encephalitis were children from 1 to 14 years old who had no or uncertain history of vaccination.As analyzed by linear regression,the incidence of Japanese B encephalitis infection statistically correlated with the paddy acreage and average annual rainfall.It is concluded that epidemics of Japanese B encephalitis infection in Guangdong province shows some endemic character and obviously periodic recurrence as well as seasonal variation.Vaccination and anti-mosquito measure appear to be most important to control the spreading of Japanese B encephalitis infection.