The ultimate goal of tooth regeneration is to replace the lost teeth. Stem cell-based tooth engineering is deemed as a promising approach to the making of a biological tooth (bio-tooth). Dental pulp stem cells (DPSCs) represent a kind of adult cell colony which has the potent capacity of self-renewing and multilineage differentiation. The exact origin of DPSCs has not been fully determined and these stem cells seem to be the source of odontoblasts that contribute to the formation of dentin-pulp complex. Recently, achievements obtained from stem cell biology and tooth regeneration have enabled us to contemplate the potential applications of DPSCs. Some studies have proved that DPSCs are capable of producing dental tissues in vivo including dentin, pulp, and crown-like structures. Whereas other investigations have shown that these stem cells can bring about the formation of bone-like tissues. Theoretically, a bio-tooth made from autogenous DPSCs should be the best choice for clinical tooth reconstruction. This review will focus on the location, origin, and current isolation approaches of these stem cells. Their odontoblastic differentiation and potential utilizations in the reconstruction of dentin-pulp complex and bio-tooth will be extensively discussed.