Objective To summary the characteristics of adult stem cells and to introduce the definition and the features of stem cell disease.Methods Literature concerning adult stem cells and stem cell disease was extensively reviewed.Results Adult stem cells were localized in tissues and organs, and were able to generate function cells to replace cell loss during a lifetime of wear and tear. The stem cells had selfrenewal to maintain themselves and undergo aging within the lifespan of an organism. The dysfunction of stem cells was capable to cause diseases, which could be defined as stem cell disease in human. The disorder of self renewal and differentiation in stem cells could increase the cellular proliferation, produce proliferative diseases such as tumors. The stem cells with self renewal defect, differentiation blockage, or aged stem cells could not supply enough function cells for tissue refreshment. The defect of tissue refreshment caused degenerative diseases.Conclusion Studies on the stem cell self renew, differentiation, and aging can provide knowledge to understand the mechanism of stem cell diseases and develop technique to diagnose and treat these diseases.