Human caliciviruses were detected from stool specimens collected from infants with diarrhea from Beijing and Anhui Province by using RT PCR PCR products with molecular weight around 330 were obtained by using the primer pair of 289/290,which is proved to be able to amplify both Norwalk like and Sapporo like human caliciviruses The PCR products amplified from specimens collected in Beijing(CR480) and Anhui(A141) were cloned into the T A cloning vector pUCm T and sequenced The cDNA fragment amplified from CR480 is 319bp in length,which is consistent with the molecular weight of the cDNA fragment amplified from Norwalk like viruses with the primer pair 289/290,whereas the cDNA fragment amplified from A141 is 331 bp in length,which is the size of the cDNA fragment from Sapporo like viruses The sequence analysis revealed that the cDNA from CR480(the stool specimen collected in Beijing) shared higher nucleotide and amino acid identities with selected Norwalk like viruses (from 60% to 97% and 62% to 99%,respectively)than with selected Sapporo like viruses(less than 58%),having the highest identity with Takl 1999 jp and ARG320,which belong to genotype Ⅱ of Norwalk like viruses The sequence of the cDNA from A141 (collected form Anhui Province) shared higher nucleotide and amino acid identities with selected Sapporo like viruses(from 68% to 92% and 75% to 96%,respectively) than with selected Norwalk like viruses(less than 52%) It suggests that both Norwalk like and Sapporo like human caliciviruses are circulating in China and cause diarrhea in infants and young childeren Human caliciviruses were detected from stool specimens collected from infants with diarrhea from Beijing and Anhui Province by using RT PCR PCR products with molecular weight around 330 were obtained by using the primer pair of 289/290, which is proved to be able to amplify both Norwalk like and Sapporo-like human caliciviruses The PCR products amplified from specimens collected in Beijing (CR480) and Anhui (A141) were cloned into the TA cloning vector pUCm T and sequenced The cDNA fragment amplified from CR480 is 319 bp in length, which is consistent with the molecular weight of the cDNA fragment amplified from Norwalk like viruses with the primer pair 289/290, whereas the cDNA fragment amplified from A141 is 331 bp in length, which is the size of the cDNA fragment from Sapporo like viruses The sequence analysis revealed that the cDNA from CR480 (the stool specimen collected in Beijing) shared higher nucleotide and amino acid identities with selected Norwalk like viruses (from 60% to 97% and 62% to 99%, respectively) than with selected Sapporo like viruses (less than 58%), having the highest identity with Takl 1999 jp and ARG320, which belong to genotype II of Norwalk like viruses The sequence of the cDNA from A141 (collected form Anhui Province) shared higher nucleotide and amino acid identities with selected Sapporo like viruses (from 68% to 92% and 75 % to 96%, respectively) than with selected Norwalk like viruses (less than 52%) It suggests that both Norwalk like and Sapporo like human caliciviruses are circulating in China and cause diarrhea in infants and young childeren