In this paper we analysed the influence of water—abstracts of Huangqi on the anti — tumour effects of polyresistin oral use. Results showed Huangqi could strengthen the anti—tumour effects of polyresistin. As in the group treated with Huangqi— polyresistin the reaction of spleen T cells to Con—A stimulation increased, but the viability of tumour cells decreased. Huangqi—Polyresistin prolonged the survival term of tumourborne mice and lowered their mortaity. Based on the facts that polyresistin is peptidoglycan,Polyresistin can activate monocyte—macrophage system and Huangqi induce the production of IFN?. We think the positive regulation of IFNr on the synthesis and cytotoxic—effect of TNF? may be one of the most important mechanisms of Huangqi to strengthen the anti— tumour effects of polyresistin.