Clausena lansium (Lour.) Skeels is a fruit tree as well as medicinal plant. Its bark was selected as a raw material for extracting condensed tannins. In this study, the anti-alpha-glucosidase and antityrosinase activity, anti-proliferative and apoptotic properties in B-1(6) mouse melanoma cells of condensed tannins from Clausena lansium bark (CBCTs) were evaluated. The results confirmed that CBCTs greatly inhibit the activities of a-glucosidase and tyrosinase, and the IC50 values were calculated to be 0.60 +/- 0.01 and 8.5 +/- 0.2 mu g/mL, respectively. CBCTs were mixed competitive inhibitors of alpha-glucosidase and non-competitive inhibitors of tyrosinase. The driving forces for CBCTs binding to alpha-glucosidase and tyrosinase were mainly hydrogen bond and hydrophobic force. Furthermore, the CBCTs could inhibit proliferation and induce apoptosis in B(16 )mouse melanoma cells. Therefore, this study demonstrated a novel alpha-glucosidase inhibitor and tyrosinase inhibitor, and would provide scientific evidences in the development of anti-diabetic and skin diseases agents.