Fecal samples of calf diarrhea were taken on farms in Jeju island, rotavirus was isolated and cytopathic effect (CPE) was determined after infection to MA104 cell. Morphological evaluation on electron microscopy proved it as rotavirus. Also, its infection to MA104 cell was reidentified using a fluorescence antibody method. Genotype of Jeju island bovine rotavirus (JBR) analyzed through PAGE was 4: 2: 3: 2 pattern, which was unique in bovine and that analyzed through general PAGE was somewhat different from NCDV, UK, KK3, A5-3A, 61A, B223 and similar to N stool-5, N culture-5 and Kawatabi (Japan). By titration after plaquing, the level was $1-3;{ imes};10^6;PFU/ml$, which was lower than those of NCDV and UK. Electrophoresis analysis of RNA-RNA hybridization, ELISA, and first and second PCR products of VP7 and VP4 in 1% agarose ($TAE+1{mu}l$ EtBr) revealed that the rotavirus was a serotype of G6P11.