Autologous fat transplantation for soft tissue augmentation has become a popular since its introduction in the late of 1800s. However, there are some limitations including unpredictable and continuos resorption after fat transplantation. Adipose derived stem cells(ASCs) are a promising cell source for adipose tissue engineering due to their plasticity and multilineage potential in vitro and in vivo. Previously, we demonstrated that adipogenic differentiation of ASCs before transplantation could successfully enhance adipose tissue regeneration. Further, clinical trial showed effectiveness of autologous differentiated adipocytes therapy for treatment of soft tissue defects. Recent advances in tissue engineering have demonstrated the feasibility of using scaffold to overcome limitations of conventional 2-dimensional(2-D) culture system and to enhance therapeutic efficacy. Scaffold for adipose tissue engineering should be injectable and biodegradable as a cell delivery vehicle as well as provide a favorable surface for cell adhesion, proliferation and differentiation. In this study, we used collagen-based microbeads to assess the ability of human ASCs to proliferate and differentiate into adipocytes on microbeads. Human ASCs were seeded onto microbeads and differentiated with adipogenic condition. Cell growth, differentiation, function and in vivo adipose tissue formation were evaluated by fluorescence image analysis, Oil red O and Nile red staining, enzyme-linked immunosorbent assay, and immunohistochemistry. ASCs attached and proliferated well on the microbeads and the number of cells increased more than 7 times for 8 days of culture. Cells grown on microbeads were differentiated into adipocytes with higher efficiency than 2-D culture system based on differentiation rate and leptin secretion. When adipocytes differentiated on microbeads were injected into nude mouse subcutaneously microbeads were degraded over time and adipocytes formed new adipose tissue. This study suggests that adipocytes cultivated on appropriate scaffold may have significant utility in the adipose tissue engineering.