The digoxigenin (DIG) labelled cDNA probe of rotavirus was directly prepared by polymerase chain reaction (PCR). The results of cDNA-RNA hybridization showed that the DIG-cDNA probe exhibits rotavirus specificity and can detect as tiny as 10 pg rotavirus RNA. 120 fecal samples of diarrhea from infants and young children were tested by dot-blot hybridization. It was shown that the positive rate of dot-blot hybridization(65.0%) was significantly higher than that of PAGE(49.1%). This study indicated that direct preparation of DIG-labelled rotavirus-cDNA probe by PCR is much faster and simpler than common method of labeling.