Although there are several methods for establishment of stem cell line, most of them has critical limit such as, ethical problem and infectious concern. Accordingly, we investigated the cell fusion technique as a new tool to establish a stem cell line. We cultured mouse embryonic stem cell (ESC) and somatic cells. Then, these two type cells were fused by electro cell fusion that consist of three steps (AC→DC→AC). The fused cells were individually transferred into a 96-well plate and cultured in ESC culture medium for 6 ~ 7 days. Newly formed colonies were evaluated several analysis methods like morphology, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins, and karyotyping. The fusion efficiency from the ESC and somatic cell into colony formation was about 0.3 ~ 0.5 %. The electro cell fused (EF) new stem cell colonies (EF-SC1 ~ 4) were indicated normally round-shape morphology similarly to ESC colonies and each colonies were expressed green fluorescent protein that having somatic cells. Also, all EF-SC groups were highly expressed AP activity and pluripotency marker proteins, POU5f1, NANOG, SOX-2 and SSEA-1. In the transcription levels, all EF-SC groups were significantly higher level of expression in Pou5f1 and Nanog compared to donor cells (ESC and somatic cell) (p<0.05). In particular, the level of Pou5f1 expression was about 2-folds higher in EF-SC2 and EF-SC3 groups than in control and EF-SC1 groups (p<0.05). Also, the level of Nanog expression was very significantly higher in EF-SC2 group (3.5-folds) compared to control ESC group, and the expression levels among treatment groups were variable (ESC<EF-SC1<EF-SC4<EF-SC3<EF-SC2, p<0.05). In karyotype analysis, the results of EF-SC2 and EF-SC3 were presented the same that of ESC, while that of EF-SC1 and EF-SC4 shown aneuploid mutation in chromosome 8. Taken together, these results demonstrate that electro cell fusion technique can be used as a new method to establish of stem cell lines.