Abstract: ObjectiveTo explore the genetic characteristics of VP1 gene of enterovirus 71 strains isolated in Linyi, Shandong province,2009-2010 and to analyze the relationship between variations of VP1 gene and different clinical types.MethodsThe VP1 genes of 23 enterovirus strains isolated from stool and throat swab specimens of hadn-foot-and mouth disease(HFMD)cases were amplified with reverse transcription-PCR(RT-PCR)and their sequences were analyzed with DNASTAR 6 and MEGA 4.ResultsThe homology between the 23 strains and the reference strains of subtype A and B was relatively low.The homologies of nucleotide and the amino acid of the 23 strains with the reference strains of group C4a were 92.8%-93.5% and 98.3%-99.3%,respectively,indicating that there was a close relationship between them.Comparisons of amino acid sequences among the 23 strains showed that there were no characteristic variations.ConclusionThe enterovirus 71 strains isolated in Linyi,Shandong province belonged to the group C4a of subtype C4,and there were no characteristic variations in nucleotides or amino acids among HFMD cases,severe cases or death cases.