Objective: Bone is connective tissue with various functions such as protection, movement, support of different organs of body, calcium homeostasis and mineral storage. Osteoblast cells of bone are responsible for extracellular matrix production and mineralization process. Thus osteoblast playing important role in bone formation and bone diseases. For repair of non-healing bone defects or treatment of bone disease it is important to access of effective methods. Recently, engineering of bone tissue is the best candidate for clinical applications. Therefore the differentiation of osteoblast from stem cell is necessary for tissue engineering of bone. Human mesenchymal stem cells from adipose tissue were promised as source for therapeutic regeneration. Adipose-derived stem cells have muli potently by means the ability to differentiate in to the kinds of cells and there are able self renewing. Therefore these cells can be used for engineering of bone tissue in order to treatment of disease and disorder of bone. Material and Methods: Therefore in present study adipose-derived stem cells were induced in to osteoblasts and their osteocalcin production of osteocalcin was investigated by western blot method. Osteocalcin is a 49residue (5.8KD) polypeptide which is synthesized by osteoblast and it is a specific marker of bone formation. Results: Our results indicates the existence of osteocalcin in differentiated osteoblast from stem cells. Conclusion: These data indicate the differentiation the osteoblast from stem cells is obtained.