There were several outbreaks of epidemic diarrhoea in adult ocouring from march 1982 for two years in some areas of Heilone-Jiang province. A kind of Rotavirus-like virus particles was found by EM and IEM.This virus particles presented two forms in morphology. The average diameter of one form was 52nm.It was detected in the supernatant fluid of stool samples in 64.6% of the cases by negative staining (Fig 1 and 3 IEM). The average diameter of the other form was about 70nm which was found in the pellet by ultrathin sectios in 86.4% of the cases.The 70nm particle is the mature and complete virus particle while the 52nm particle is the core without capsomers. This virus is diffrent from ordinary rotavirus and reovirus by IEM and ELISA We designate this virus temporarily as new rotavirus.