Somatostatin can suppress the growth of various tumor cells including colonic cancer. Activated Wnt/beta-catenin signaling pathway plays a critical role in tumorgenesis and development of colorectal cancer. However, the effect of somatostatin on Wnt/beta-catenin signaling pathway remains unknown. Thus, we investigated the effect of octreotide on Wnt/beta-catenin signaling pathway in human colonic cancer cell SW480. The results of 3-(4,5-imethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and flow cytometric assays showed that octreotide inhibited growth, induced apoptosis and arrested the G, cell cycle of SW480 cells in a dose-dependent manner. We demonstrated that octreotide significally up-regulated and down-regulated 13 genes and 17 genes in Wnt/beta-catenin signaling using microarray, respectively. Furthermore, as evidenced by western blot, beta-catenin protein level decreased, whereas phosphorylated P-catenin protein level increased under octreotide. The present study reveals that octreotide can inhibit human colonic cancer cell growth through inhibition of Wnt/beta-catenin signaling pathway.