This book provides a comprehensive introduction to various types of perinatal stem cells. Given their unique regenerative abilities, stem cells offer a promising avenue in the treatment of degenerative diseases or injury.  Currently, the limitations of postnatal cell sources and expanding efficiency may limit autologous stem cell therapies. Although embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can be cultured indefinitely ex vivo, and can differentiate into three germ layers, ethical issues, the teratoma formation of ESCs and oncogenic risk of iPSCs are major obstacles to their clinical application. More recently, perinatal stem cells have been isolated from the umbilical cord, Wharton s Jelly, placenta, amniotic membrane and amniotic fluid, which are normally discarded as medical waste.