The repair of the tendon-bone interface, which is composed of tendon, fibrocartilage, and bony attachment, remains a clinical challenge. The application of mesenchymal stem cells (MSCs), collagen-rich extracellular matrix (ECMs), as well as growth factors, has the potential to regenerate this special multiple-tissue structure through the so-called biological augmentation. We present here an in vitro tendon regeneration model with C3H10T1/2 cells cultured on Collagen I matrix and evaluated the lineage determination effects of Growth Differentiation Factor 7 (GDF-7). We found that besides tenogenic effect, GDF-7 also stimulates the expression of osteoblastic as well as adipocytic genes. Our results indicate that GDF-7 might be a promising growth factor for regeneration of the tendon-bone interface due to its multiple-lineage stimulating effects. However, the side effect on adipogenic differentiation should be of concern, as it is a known risk factor for repair failures.