The purpose of this research was to investigate the effect of reaction-precipitate from Coptidis Rhizoma and Glycyrrhizae Radix aqueous mixture(CGP) on the cytotoxicity. The effects of CGP on the growth of tumor cells, Balb/c 3T3 cell, mouse spleen cell and human lymphocyte were compared with those of berberine, glycyrrhizin and berberine glycyrrhizinate(BG), which were estimated by MTT colorimetric assay or cell counting. CGP, berberine and BG inhibited the growth of several tumor cells, such as Hep G2, A549, Raji, MCF-7, HeLa and KHOS-NP. Whereas, glycyrrhizin inhibited the growth of Raji and MCF-7, CGP did not affect on Balb/C 3T3 cells, mouse spleen cells and human lymphocyte at $10^{-6}{sim}10^{-5}g/ml$. CGP increased the number of leukocyte in mice. This results indicate that CGP have the inhibitory action of the growth of human tumor cells, and the side effect of CGP is less than berberine and BG.