Abstract: This work aims to clone gene fragment of Cucumber mosaic virus（CMV）from pepper LJ-10 in Xinjiang，to analyze the sequence，construct the prokaryotic expression vector of CMV CP gene，and to prepare CP’s polyclonal antibodies. The complete genome fragments of RNA1（3 357 nt），RNA2（3 042 nt），and RNA3（2 212 nt）were cloned by RT-PCR，and compared with different CMV isolates from CMV subgroup IA，subgroup IB and subgroup II in the GenBank by sequence analysis and phylogenetic tree analysis. The CP gene of CMV in LJ-10 was cloned into prokaryotic expression vector pET-22b and expressed in Escherichia coli BL21（DE3），and the expressed proteins were purified. Rabbit was immunized with the purified protein to prepare the antiserum with CMV-specificity，and detected by indirect ELISA test and Western blot. As results，the genomes of RNA1，RNA2，and RNA3 were successfully cloned，the sequence analysis and phylogenetic tree analysis showed that the isolates belonged to CMV subgroup IB. The prokaryotic expression vector pET-CMV-CP was successfully constructed and expressed as a 27 kD recombinant protein in E. coli BL21（DE3）by IPTG induction，and whose molecular weight was identical to the expected one. The indirect ELISA test and Western blotting showed that the antiserum’s titer was 1：500-1 000. In conclusion，the CMV isolate from LJ-10 belongs to CMV subgroup IB. The prokaryotic expression vector of CMV CP gene from LJ-10 is successfully constructed，and the corresponding polyclonal antibody is prepared.

Key words: Cucumber mosaic virus, sequence analysis, coat protein gene, prokaryotic expression, Western blot