Ectopic expression of four transcription factors including Oct4,Sox2,KIf4 and c-Myc in differentiated fibroblast cells could reset the cell fate of fibroblast cells to pluripotent state.Subsequently,full pluripotency of these so-called induced pluripotent stem cells (iPSCs) has been demonstrated in our lab as viable mice could be generated autonomously from iPS cells through tetraploid blastocyst complementation.In this talk,I will briefly summarize the recent progress in our laboratory in understanding the pluripotency of iPS cells.Furthermore,I will further introduce the advances that we achieved recently in understanding the molecular mechanism of both somatic cell nuclear transfer and defined transcription factors mediated somatic cell reprogramming.