tool specimens were collected form children with diarrhea in the autumn and winter of 1991 form Beijing ,ChangchunmXingtai and Shantou,located in the north,northeast and south of China.out of 5540 specimens collected,334 (60.7% ) were positive for rotaviruses as deter-mined by polyacrylamide gel electrophoresis (PAGE).VP4 and VP7 genotypes of the viruseswere identified by Northern blot hybridization analysis using 32P labeled VP4 and VP7genotype specific cDNA clones as probes.The data indicated that most of...