Abstract: The objectives of this study are to acquire trichosanthin（rTCS）and to explore the effect of rTCS combined with YH-16 on the proliferation of melanoma B16-F10 and xenograft tumor growth in mice model. rTCS was expressed in Escherichia coli BL21 strain and purified by Ni affinity chromatography. Then the effects of rTCS，YH-16，and combination of rTCS with YH-16 on the cell growth were determined by MTT assay and in vivo trial. Results were as：pure recombinant rTCS protein was obtained. The proliferation of B16-F10 was inhibited significantly by rTCS，and inhibition rate was significantly higher than by YH-16 alone，however，no significant difference between rTCS alone and the combination of rTCS and YH-16. The xenograft tumor growth in the group treated with the combination of rTCS and YH-16 was significantly smaller than the ones by rTCS-treated alone or control. In conclusion，the combination of rTCS with YH-16 presented significant inhibitory effect on proliferation of B16-F10 as well as on xenograft tumor growth，and this strategy with the combination would provide new opportunity for treating melanoma patients.

Key words: trichosanthin, YH-16, B16-F10, tumor, combination therapy