ITS DNA sequences of two variants of Pinus spp. having single fasciculate leaf or two to three fasciculate leaves within an individual were analysed in order to determine their origin. Also, the same DNA locus of P. densiflora, P. rigida and P. koraiensis, distributed at the same region together with the OTUs having leaf variations, were analysed to compare with each other. Aligned sequences including ITS1, 5.8S and ITS2 were 580~584 bp in length. The 5.8S region was well conserved among all the OTUs we tested except for P. koraiensis, which has two nucleotide substitutions. The partial ITS1 region upstream of the 5.8S region showed relatively high sequence diversity compare to the ITS2 and has 181~185 bp in length. In this region, the sequences of the two variants were identical to that of P. densiflora. The ITS2 has identical for all OTUs in length and the two variants also have same sequences compare to that of P. densiflora. These two variants and samples of P. densiflora were grouped together in the UPGMA tree with 100% similarity level. The result strongly suggest that these two variants were originated from P. densiflora.