Abstract: By the previous studies, it was reported that the TMV gene exsists only in cytoplasm and the splicing of pre-mRNA, which occures in nuleus, does not happen in cytoplasm. But in this study, we found that the expression of GUS harbored in vector of TMV coincided with intron splicing of pre-mRNA. In an attempt to use TMV vector to express a fusion protein in Nicotiana benthenmiana , a GUS gene with an intron was cloned into the vector, Supprisingly, the GUS gene was expressed at high level. Reverse-transcription and polymerase chain reaction(RT-PCR), DNA sequencing and GUS-INTRON gene mutant analyses of transcripts show an event of intron splicing happened with the GUS gene.