Abstract: Cell reprogramming refers to the transformation of gene expression within a cell from one type to another,and that is defined as the converting process of somatic cells to pluripotent or totipotent stem cell by differentiation or to another type of somatic cells by transdifferentiation under certain conditions. Cell reprogramming provides infinite cell resources for clinical patient-specific cell therapy. It can be achieved by somatic cell nuclear transfer,transfecting specific transcription factor,and induction with small molecule compounds. However,the somatic nuclear transfer technique is thought to have ethical issues because of using oocytes;and the integration of transcription factor into the host genome leads to gene mutations,which greatly limits their clinical application. Small molecule compounds are easy to be synthesized,have fine cell permeability and flexible biological effects. The use of small molecule compounds to induce cell reprogramming avoids the ethical issues from nuclear transfer the potential harm from gene manipulation. At present,the small molecule compounds are used to induce safer iPSCs（induced pluripotent stem cells）,ciCMs（chemically induced functional cardiomyocyte cells）,and ciNSLCs（chemical-induced neural stem cell-like cells）from somatic cells. Here we summarize different kinds of cell identity conversions induced by small molecule compounds,referring to induced pluripotent stem cells,induced extended pluripotent stem cells and induced cell transdifferentiation,and finally prospect the future development of induction by small molecule compounds,the purpose is to provide reference for future research in this field.

Key words: cell reprogramming, cell transdifferentiation, small molecule compound