Abstract: According to published nucleotide sequence, coat protein (CP) gene of sweet potato virus G(SPVG) isolated from Henan province was cloned and sequenced. The results of sequence analysis showed that the CP gene consisted of 1065 nt encoding 355 amino acid residues. The CP gene nucleotide sequence were about 98% identical to Egypt1(AJ515380), LSU-1(AY178991), LSU-3(AY178990) and SPVG-CH（X76944）isolates, respectively, and were 85.5% identical to SPVG-CH2（Z83314）isolated from Guangdong province. The CP gene was constructed into expression vector pET30a（+）for overexpression in prokaryotic cells. The result of SDS-PAGE showed that about 39 kDa specific fusion protein was produced after induction by IPTG. The expressed protein was purified from SDS-PAGE and the antiserum against the protein was raised in rabbit. The antiserum was used for specific detection of SPVG from field samples of sweet potato by ACP-ELISA.