Abstract: Objective To study pathogenic effect of enterovirus 71(EV71)VP2 protein on cell injury.Methods SDLY 11 strain was isolated from a child patient with mild symptom of hand,foot and mouth disease(HFMD) and SDLY 107 strain was isolated from a child patient with severe symptom of HFMD.Amino acid sequences of VP2 protein were analyzed by MEGA 4 software.On the basis of genome sequences of SDLY 11 and SDLY 107,we designed the primers for the region of VP2.We built the expression vectors VP2-pBluescriptSK(+) and expressed VP2 protein in Vero cells by transfection in vitro.Lactate dehydrogenase(LDH) test was used to detect the cell injury caused by VP2 protein of diffenent EV71 strains.Results One different amino acid in VP2 protein(V199I) was found between SDLY 11 and SDLY 107.VP2 protein from SDLY 11 and SDLY 107 could be expressed in Vero cells;the results of LDH experiment showed no difference in cell injury caused by VP2 proteins of the two EV71 strains.Conclusion VP2 protein of the EV71 strains from patients with different clinical symptom may have no difference in the effect on cell injury.The result provides an important basis for the study of EV71 pathogenesis mechanism.