The establishment of reverse genetic system of foot and mouth disease virus(FMDV) is important for study of the molecular pathogenesis and prevention of the foot-and-mouth disease.In this study,4 overlapped cDNA fragments spanning the entire genome of the FMDV O/YS/CHA/05 strain was assembled in a low-copy vector pOK12 and co-transfected into BHK cells with the plasmid that expresses T7 RNA polymerase.Typical FMDV CPE was developed following transfection.The rescued virus was identified by IFA,molecular Marker,and detecting one-step growth curve.This stable infectious clone is an important tool for study molecular pathogenesis of FMDV and development of novel vaccine against FMDV.