AIM: To study the effect of caffeic acid phenethyl ester (CAPE)on proliferation, cell cycle, apoptosis and expression of β-catenin in cultured human colorectal cancer (CRC) cell line HCT116.METHODS: HCT116 cells were treated with CAPE at serial concentrations of 80, 40, 20, 10, 5, 2.5 mg/L. The proliferative status of HCT116 cells was measured by using methabenzthiazuron (MTT) assay. Cell cycle was analyzed by using flow cytometry (FCM) with propidium iodide (PI) labeling method. The rate of apoptosis was detected by using FCM with annexin V-FITC and PI double labeling method.β-catenin levels were determined by Western blotting.β-catenin localization in HCT116 was determined by indirect i mmunofluorescence.RESULTS: After HCT116 cells were exposed to CAPE (80,40, 20, 10, 5, and 2.5 mg/L) for 24, 48, 72, 96 h, CAPE displayed a strong growth inhibitory effect in a dose- and time-dependent manner against HCT116 cells. FCM analysis showed that the ratio of G0/G1 phase cells increased, S phase ratio decreased and apoptosis rate increased after HCT116 cells were exposed to CAPE (10, 5, and 2.5 mg/L)for 24 h. CAPE treatment was associated with decreased cytoplasmic β-catenin, nuclear β-catenin and a concurrent increase in β-catenin protein expression at cell-cell junctions.CONCLUSION: CAPE could inhibit HCT116 cell proliferation and induce cell cycle arrest and apoptosis. Decreased β-catenin protein expression may mediate the anti-proliferative effects of CAPE.