Abstract: This paper reported the experimental results of toxicological effect of maibingzhi. The LD 50 and the cumulation test showed that maibingzhi is a low toxic and low cumulation substance. A battery of short term both in vitro and in vivo mutagenic test systems with different hereditary detecting endpoints were employed for the study of genotoxicity of maibingzhi. The results also showed that maibingzhi with four doses (0.005～5 mg/ml) did not induce positive mutations for strains of TA 97 , TA 98 , TA 100 and TA 102 with or without Sgmix in the Ames test. Maibingzhi did not induce increasing micronucleus rate by the experiment of frequency of micronucleated polychromatic erythrocytes in mouse bone marrow. No chromosome aberration of reproductive system was found by the test of pathological morphological changes of spermatozoa. It did not cause the bad effects on SD mouse reproduction ability and embryo growth and development. In addition, it did not cause the deformity of the fetus appearances, bone and internal organs.