Abstract： Objective To study the inhibitory effects of Protankyra Bidentata anti-tumor factor(PBATF)on the growth of tumors implanted in mice or rats.Methods Methods of H22 liver cancer implanted in Kunming mice,Walker-256 sarcoma implanted in Wistar rats,human LAX lung cancer and human QGY liver cancer implanted in nest mice were used to detect the inhibitory effects of PBATF on the tumor growth,respectively.Animals in each model were divided into 5 groups:hish PBATF group(5 mg/kg),middle PBATF group(1 mg/kg),low PBATF group(0.5 mg/kg),positive control group(CTX)and negative control group.The preparations were administrated once a day,for 7-10 days.The LD50 peritoneal injection of PBATF was detected according to ordinary method.Results The inhibitory tumor rates of PBATF on Walker-256 sarcoma implanted in Wistar rats,human LAX lung caner implanted in nest mice,human QGY liver cancer implanted in nest mice and QGY liver cancer implanted in nest mice were 62.63%,56.02%,52.07% and 59.25% in high dose group,52.31%,50.60%,45.56% and 57.74% in middle dose group,37.49%,40.36%,33.14% and 45.28% in low dose group,respectively.The LD50 peritoneal injection of PBATF was 1.973 g/kg.Conclusions PBATF hag significant inhibitory effect on tumor growth in vivo.