Objective: Mesenchymal stem cells are multipotent stromal cells which show heterogeneity with self-renewal and multilineage differentiation potency. The aim of this study is analysis and comparing potential for clump formation of bone marrow and adipose tissue derived mesenchymal stem cells (BMSCs & AMSCs). Materials and Methods: Bone marrow and adipose tissue derived stem cells are isolated and cultured. Morphology and viability of the cells are evaluated using hematoxilen-eosin and tripan blue staining method consequently. Clump formation of the cells is studied until passage 10 (P10). All clumps with < 2 mm diameter or with no stain are excluded. Both types of clumps are induced using osteogenesis and adipogenesis mediums for differentiate to osteocyte and adipocyte, consequently. Mediums are changed regularly every 3-4 days. Differentiation to adipose tissue are confirmed by the cellular accumulation of neutral lipid vacuoles are seen using oil-red staining and mineral production and deposition are seen using alizarin-red staining,about 3 weeks after serial induction. Results: Growth rate, proliferation speed,and potency of clump formation was more in AMSCs (p<0.05). Both types of the cells had relatively the same morphology and were similar to spindle shape fibroblast but cells in clumps derive from bone marrow had more obvious spindle shape. Two types of clumps showed different morphology. AMSCs made more clumps. Degeneration speed in adipose derived clumps was more than other one. Differentiation rate in AMSCs was more than BMSCs. Conclusion: Functions such as proliferation rate,viability, clump formation, and differentiation of stem cells are studied from two different anatomical sites. Results of this study showed that AMSCs are a more reliable source of seed cells with multiple merits such as minimal invasion, low morbidity, abundant yield, easy isolation, rapid expansion, good differentiation, and high potency in colony formation.