In this study, the potato leafroll virus（PLRV） Coat Protein（CP） gene was cloned, its codon was modified to favor prokaryotic expression, and the pCzn1-PLRV CP recombinant expression vector was constructed, which was expressed and purified by E. coli. The purified protein was identified as PLRV CP protein by Western Blot. The purified protein was immunized with Japanese rabbit, and PLRV CP polyclonal antibody was successfully prepared. The recombinant protein was identified as 128 000 times, and the PLRV leaf was identified as 32 000 times. The specificity was good after Western Blot analysis. This study provides necessary biomaterials for the establishment of PLRV detection method and the detection of virus-free seed potato.