This study was conducted to see what types of bovine rotaviruses were isolated at Jedong farm in Jeju province and Seohwa farm in Chungnum province. The results were as follows. 1. Rotavirus was positively detected in 18 out of 39 fecal samples from calves with diarrhea in Jeju province and in 13 out of 18 fecal samples from calves with diarrhea in Chungnam province. 2. The electropherotype pattern of dsRNA for 31 viruses was shown to be 4 : 2 : 3 : 2 type like traditional group A and the imigration pattern of dsRNA was the long type like NCDV (G6), JBR (G6), B223 (G10) and KK3 (G10). 3. The serotypes of the 18 viruses of Jedong and 9 viruses of Seowha were shown to be group A, subgroup I, G6, and P1 by ELISA and PCR analyses. The serotypes of S-2, S-6, S-9 and S-12 viruses of Seowha were shown to be group A, subgroup I, G10, but was not shown to be P type. 4. The partial nucleotide sequence of VP4 of S-8 was 97% homology with that of BRV 033. VP4 of J-10 showed 96% homology with that of BRV 033 in nucleotide sequence.