Abstract: In order to identify the subgroup type of CMV(Cucumber mosaic virus) in Hubei tobacco,CMV HB24 strain was isolated,and the full-length cDNA sequence of genomic RNAs of the isolate was determined by RT-PCR and sequence analysis.The results showed that:HB24 RNA1(GenBank:KC019299) consisted of 3363 nucleotides(nt) and encoded 1a protein of 993 amino acid residues(aa),RNA2(GenBank:KC019300) consisted of 3049 nt and encoded 2a protein of 859 aa and 2b protein of 111 aa,RNA3(GenBank:KC019301) contained 2216 nt and encoded 3a protein of 279 aa and CP of 218 aa.The results of nucleotide sequence similarity indicated that:the similarities of HB24 RNAs with the RNAs of Fny,SD,Q strains were:RNA1:91.6%,91.1%,75.9%;RNA2:91.8%,97.8%,69.5%;RNA3:92.1%,93.4%,73.2%,respectively.The similarities of HB24 RNAs with the RNAs of PSV-ER(Peanut stunt virus) were RNA1:65.5%,RNA2:56.7%,RNA3:54.1%;and that with the RNAs of TAV-V(Tomato aspermy virus) were 66.9%,57.7%,51.5%,respectively.According to RNA3 5' NTR(Nontranslated region) structure analysis,and phylogenetic tree analyses of RNA3 5'NTR and CP gene nucleotide sequences,HB24 belonged in CMV IB subgroup.