Objective: To investigate the effects and the possible mechanism of curcumin on the proliferation and the invasion of human hepatocellular carcinoma in vitro and in vivo. Methods: HCCLM3-RFP cell lines were maintained in DMEM medium supplemented with 10% fetal bovine serum. The fluorescent areas of HCCLM3-RFP were photographed daily and repeated in 4 consecutive days after curcumin treatment for obtaining cell growth curves. The cell morphologic changes were also observed. Cell invasion experiment was performed with Boyden chamber array. The RFP-expressing human HCC xenograft model in nude mice was established to study the anti-tumor effects of curcumin. The CTC was detected by FACS. The expression of cyclinD1 and MMP-2 was detected by SYBR Green Real-time PCR. Results: After incubation with 20 M, 10 M and 5 M curcumin respectively for 24, 48 and 72 hours, the growth of HCCLM3-RFP was significantly inhibited and some morphologic changes were observed. The mean tumor size in nude mice treated with curcumin since day 21were significantly less than those of the control group(p 0.01). The mean metastasis area of lung and the number of CTC in curcumin group on day 35 were remarkably less than in the control group(p 0.01). The mRNA levels of cyclin D1 p 0.01 and MMP-2 p 0.05 in curcumin group on day 35 were significantly lower than in the control group.