In order to investigate the inhibitory effects of all trans-retinoitc acid (ATRA) on differentiation and apoptosis of Walker-256 hepatocellular carcinoma cells and the therapeutic effects of ATRA combined with transarterial chemoembolization (TACE) on rat Walker-256 transplanted hepa-tocarcinoma, Walker-256 hepatocarcinoma cell lines were treated with ATRA at different concentrations. After culture for 48 h, the inhibitory rate of cell proliferation was determined by MTT assay; the changes of Fas and Bcl-2 mRNA expression were determined by RT-PCR, and the expression levels of Caspase3 and Caspase8 proteins were detected by West blot. Twenty-seven Wistar rat models of hepatocarcinoma were set up successfully by implanting Walker-256 cell lines. The tumor volume at the 11th day after implantation (Vpreoperatioi) was measured by magnetic resonance imaging (MRI). The 27 rats were randomly and equally divided into three groups, and the therapy scheme was performed as follows: group A (ATRA 0.1 mg+mitomycin 0.05 mL+lipiodol 0.05 mL+gelfoam powder 0.025 mg); group B (mitomycin 0.05 mg+lipiodol 0.05 ml+gelfoam 0.025 mg; group C (0.9% NaCl 0.2 mL). After another 11 days, MRI was performed once again to measure the tumor volume (Vpostoperation)- The expression of factor VIII and Ki-67 in the tumor tissues was detected by immuno-histochemistry. The results showed that ATRA could suppress proliferation of Walker-256 cell lines. After treatment of Walker-256 cell lines with ATRA, the expression of Fas mRNA was significantly up-regulated and the Bcl-2 mRNA was significantly down-regulated by ATRA at the concentration of 10 umol/L as compared with the control group (P<0.05). After treatment with 10 umol/L ATRA for 48 h, the Caspase3 and Caspase8 were significantly activated as compared with the control group (P<0.05). Significant difference existed in growth rate among the three groups (P<0.01) and between either two groups (P<0.05). The expression rate of factor VIII and Ki-67 was gradually increased from group A, group B to group C. The study suggests that ATRA could inhibit the proliferation of Walker-256 cells and the effectiveness of the combined therapy (ATRA+TACE) for treating transplanted hepatoma of rats is superior to that of TACE alone.