ObjectiveTo study the  clinical and epidemiological characteristics of infants acute diarrhea caused by cluster A rotavirus（RV） in changsha. MethodsStool samples from infants with diarrhea in a hospital from May 2006 to April 2007 were detected by technique of colloidal gold and immunochromatography double antigen sandwich assay. Epidemiological data of infants were analyzed. ResultsAmong 1 724 detected stool samples, 342 (19.84%) cases were positive RV antigen, the positive rate of RV antigen  from May to June in the year of 2006 was 9.21%, while from November to December in 2006 and January to February in 2007 was 36.61% and 24.37% respectively, there were significant differences in the positive rates of RV antigen between the latter two periods and the other months (χ2=107.18, P＜0.001); The most susceptible age of the infection was 6 months ~ 1 years old, ~1.5  and ~2 years old, the positive rate was 26.57%, 31.48% and 29.55% respectively, there were significant differences in the positive rates of RV antigen between infants at age of 6 months ~2 years old and the other age groups (χ2=79.30, P<0.001); RV infection rate in male and female was 16.27% and 23.94% respectively, the former was obviously lower than the latter (χ2=15.87, P<0.005). ConclusionThe incidence peak of RV infection is from November to February of the next year, the susceptible age is 6 months to 2 years old. Infants with diarrhea should be detected RV antigen as soon as possible and given rational treatment, so as to prevent transmission.