This article deals with studies in late autumn 1981 of the infection of wild adult Tupaia belangeri yunalis (a species of tree shrew caught in autumn in Yunnan province) with human rotavirus. 12 tupaias are infected in the first passage, 3 in the second passage and 3 in the third passage, 12/12, 2/3 and 2/3 of the tupaias develop diarrhea during the 3 passages. Electron microscopic observation shows that 12/12, 3/3 and 2/3 of the tupaias excrete rota-virus during the passages. Three tupaias died during the first passage and show mucosal necrosis and lymphocyte infiltration in sections of different intestinal parts. Immune electron microscopically, anti-rotavirus antibody is assayed in sera of 2 infected tupaias, in both of which titer rises greater than 4 folds in the convalescent phase serum as compared with the pre-infection serum. These results indicate that the adult tupaia is probably susceptible to human rota-virus.