SCs share unique properties: the self renewal and plasticity. These properties could be used to generate organs and tissues for transplantation. HSC sources include : BMHSC; PBHSC; UCB; Fetal liver SC and Embryonic SC, while Mesenchymal SC considered as non HSC source. However the great advances of immunology, cellular biology, embryology and transplantation technologies, the routine application of SCT is not so easily simplified. Moreover we still have to address fundamental issues such as autoimmune process, the possible tumourigeneic potential of SC-derived tissues and how to induce long term tolerance.