Abstract: ObjectiveTo investigate etiology,epidemiologic and molecular virology features of rotavirus causing infant diarrhea in Zhaotong region in autumn and winter of 2010.MethodsA total of 94 pieces of stool specimen collected from infants with acute diarrhea in the First People's Hospital of Zhaotong City from September to December,2010 were analyzed with colloidal gold test,reverse transcription-PCR,and polyacylamide gel electrophoresis and then 8 stool specimens were selected from the 94 specimens and analyzed by VP7 gene sequencing and genotyping.ResultsRotaviruses were detected in 54.3% of samples.Rotavirus genome sequence analyses showed 7 samples were G1 and one sample was G3.Phylogenetic analysis based on nucleotide sequence revealed that the rotavirus isolated in Liaoning province,India and Thailand were very similar strains.ConclusionThe infant diarrhea epidemic in the autumn and winter of 2010 in Zhaotong area was mainly caused by G1 and G3 genotype rotavirus.