Some human embryonic stem cell lines have shown genomic instabilities over long-term culture. To study the controversial origin of the SCNT-hES-1 line, which was derived from autologous somatic cell nuclear transfer (SCNT), we compared the expression and methylation patterns of imprinted genes in the SCNT-hES-1 cells with the donor's somatic cells by semi-quantitative RT-PCR, real-time PCR and bisulfite sequencing. Examined imprinted genes were H19, GNAS, SLC22A18, UBE3A and ZNF264 for maternally expressed genes, and IGF2, SNRPN, PEG3, PEG10, MEST, MAGEL2 and ARHI for paternally expressed genes, respectively. We found that the expression of imprinted genes in the SCNT-hES-1 cell line is comparable to that in the donor's somatic cells, and that its methylation patterns are similar to those of other SCNT-products. Therefore, the present study indicates that the SCNT-hES-1 line was derived from SCNT.