Inhibition of cancer-associated broblasts (CAFs) may improve the efficacy of cancer therapy. Polysaccharide extracted from polygonatum can selectively inhibit the growth of prostate-CAFs (<.001) without inhibiting the growth of normal broblasts (NAFs). Polysaccharides from polygonatum stimulate autophagy of prostate-CAFs. 3-methyl-adenine(3-MA) is an autophagy inhibitor. 3-MA was added to prostate-CAFs with polysaccharide from polygonatum to determine whether autophagy plays an important role in the restrained effect. Finally, polysaccharide from polygonatum treatment significantly increased the activation of Beclin-1 and LC3, key autophagy proteins. Polysaccharides from polygonatum stimulate autophagy of prostate-CAFs and inhibits prostate-CAF growth, indicating that a novel anti-cancer strategy involves inhibiting the growth of prostate- CAFs.