The monomer cDNA of CMV satellite RNA-I was cloned into vector pUC12 (Sma 1 site) to construct recombinant plasmid pUI. One alquot of pUI was digested with two restriction enzymes (BamH 1 and Sma 1) to separate the vector from the monomer fragment which was made to have the blunt end with Klenow enzyme, and one alquot of pUl was digested with Sma 1 to expose the 3’ end of monomer cDNA. Then the precursor of dimer cDNA was constructed via which the monomer fragment was ligated into pUI (Sma I site) and the precursor was subcloned into phagc M13 mp19. Seven bases that were not the parts of the sequences of satellite in the precursor between two monomer cDNA were deleted by the method of site-directed mutagenesis The monomer cDNA of CMV satellite RNA-I was cloned into vector pUC12 (Sma 1 site) to construct recombinant plasmid pUI. One alquot of pUI was digested with two restriction enzymes (BamH 1 and Sma 1) to separate the vector from the monomer fragment which was made to have the blunt end with Klenow enzyme, and one alf of of pU1 was digested with Sma 1 to expose the 3 ’end of monomer cDNA. Then the precursor of dimer cDNA was constructed via which the monomer fragment was ligated into pUI ( Sma I site) and the precursor was subcloned into phagc M13 mp19. Seven bases that were not the parts of the sequences of satellite in the precursor between two monomer cDNA were deleted by the method of site-directed mutagenesis