Rotaviruses are the causative agent of gastroenteritis in humans and amimals and have a worldwide distribution. Rotaviruses are classified as a genus in the family Reoviridae and comprise six serogroups (A-F). The group A rotaviruses have been widely implicated as one of the common causes of diarrheal diseases. The serotype-specificity of group A rotavirus is determined by two surface proteins, VP4 (P types) and VP7 (G types), which produce immunity. To determine the sequences of the VP4 gene of Korean isolates CAU-13, viral RNA was purified from fecal samples, and the 2635 bp size of the VP4 cDNA was amplified by the reverse transcriptase-polymerase chain reaction. The sequences of nucleotides and deduced amino acids of CAU-13 were compared with those of foreign isolates submitted to GenBank. The homologies ranged from 46.0% to 98.1% of nucleotide sequences and from 38.2% to 100% of amino acid sequences, respectively. The highest nucleotide homology of CAU-13 was observed with Japanease human strain CJN, whereas the lowest nucleotide homology was observed with Japanease human strain L26. As a result, the sequence analysis VP4 protein of rotavirus CAU-13 strain isolated from an infant in Korea may be used for designing the vaccine development strategy.