Mesenchymal stem cells (MSCs) are the most promising seed cells for cell therapy and tissue engineering, which can be isolated from various sources of human adult tissues such as bone marrow and adipose tissue.However, cells from these tissues must be obtained through invasive procedures and sometimes the individual difference is hard to control.Hence, the search continues for an ethically conducive, easily accessible and controllable source of stem cells.We herein report the isolation of a population of stem cells from the human placental decidua basalis (termed as PDB-MSCs), a maternal portion of placenta.PDB-MSCs were further shown to express markers common to MSCs and are positive for SSEA-1, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81 and Oct-4.In order to facilitate the further utility in ischemic diseases, we tested the apoptosis of PDB-MSCs in hypoxia and serum deprivation, two components of ischemia in vivo.Taken together, our findings indicate that PDB-MSCs are resistant to hypoxia and serum deprivation which may relate to Bcl-2.