To understand the molecular structure and pathogenesis mechanism of Korean garlic viruses (GV), virus particles were isolated from field-grown garlic leaves and RNA genome was isolated from them. It was used for constructing cDNA library for GV. Several cDNA clones for GV were isolated and classified into 4 different groups on the basis of cross Southern hybridization. Northern blot analysis of GV RNA with one of these cDNA clones shows that the clone is a cDNA for GV RNA.