Genotyping of human rotaviruses was performed using 55 rotavirus-positive samples collected from 90 young children with diarrhea at Chung-Ang University Yongsan Hospital between December 2001 and May 2002. G typing of the VP7 protein showed that G2 was the most dominant circulating genotype (32.8%) followed by G1 (21.8%), G4 (12.7%), G3 (10.9%), G9 (1.8%) and a combination of G2/G3 (7.3%). P typing of the VP4 protein revealed that P (60.0%) was the most prevalent strain, followed by P (25.5%), P (3.6%) and P (1.8%). Seven samples (12.7%) for G type and 5 samples (9.1%) for P type remained untypable. The most predominant G-P combination was G2P (29.1%), which is one of the most commonly observed type worldwide. A G9 serotype strain identified in this study shared more than 97% nucleotide homologies with 18 foreign G9 isolates. Therefore, incorporation of G9 rotavirus into current vaccine formula should be considered.