Abstract: Objective To explore anti -tumor effect of effective components from shenetang , so as to provide experimental basis for the development of new drugs. Methods H22 tumor model in mice was built. Mice implanted withH22 were treated with effective components from shenetang for 7d, then the tumor tissues, thymus glands and spleens were weighed. The tumor inhibitory rates, immune organ index and carbon granule clearance index were calculated to investigate the anti -tumor and immune regulatory effect of effective components from shenetang in mice implanted with tumor cells. Results Effective components from shenetang showed more potent anti-tumor effect within the dose range in 8.31～70.72g·kg^-1, it could raise the decreased immune organ index and carbon granule clearance index. Conclusion Effective components from shenetang in 8.31～34.65g·kg^-1 dose range shows a certain "dose-efficacy" relationship of anti-tumor activity. The optimal dose of anti-tumor effect is 34.65g·kg^-1 and the minimum effective dose is 8.31g·kg^-1. With the dose increasing, ina certain dose range, the inhibition enhanced, it shows dose dependency. When it achieves maximum effect, the anti-tumor effect no longer increases. The effective component can improve immune function to inhibit tumor.

Key words: Shenetang, "dose-efficacy" relationship, effective component