SKT is consisted of skullcap radix, knope-sedge radix and trametes mushroom. SKT mixture extract has been used for curing breast cancer and cervical cancer as a folk medicine without any kind of experimental evidence to support the rationales for its clinical use. This study was undertaken to investigate the antitumor effects and toxicity of SKT. Tumor was induced by implantation of B16F10 melanoma cells $(1{ imes}10^6;cells/mouse)$ into abdominal skin in ICR mice and SKT application (5 mg/mouse, p.o.) was initiated 4 days prior to tumor induction and lasted for 42 days. SKT significantly inhibited not only tumor growth but also metastasis of i.v. implanted melanoma cells into lung and showed prolonged life span of tumor bearing mice. The combined theraphy of SKT with doxorubicin was more effective against tumor metastasis into lung. SKT almostly recovered serum SGPT to normal level of galactosamine/LPS-induced hepatitis mice. High dose of SKT did not show any acute side effects. But, in vitro SKT did not inhibit the growth of melanoma cells, which suggests that the antitumor effects of SKT might be menifested by indirect mechanisms.