Objective To study the antitumor activities of Huanglianjiedu Decoction(HLJDT) in vivo and in vitro. Methods Antitumor activities were tested in mice with experimental tumor S180 and MFC in vivo, thymus index, spleen index, tumor inhibitory rate were evaluated. Cell proliferation was assayed by using methyl thiazolyl tetrazolium (MTT) method in vitro. S180, MFC, SGC-7901 and SMMC-7721 cancer cells were incubated in culture media containing HLJDT. Results HLJDT showed a Antitumor activities on S180 and MFC in vivo. All of the HLJDT in different dosage groups could highly inhibit the proliferation of 4 cancer cells. Conclusion The HLJDT could inhibit the tumor S180, MFC in mice, the drug has obvious anticancer effects against S180, MFC, SGC-7901 and SMMC-7721.