AIM: To evaluate the effect of preoperative transcatheter arterial chemoembolization (TACE) on proliferation of hepatocellular carcinoma (HCC) cells.METHODS: A total of 136 patients with HCC underwent liver resection. Of 136 patients, 79 patients received 1 to 5 courses of TACE prior to liver resection (TACE group),who were further subdivided into four groups: Group A (n = 11) who received 1 to 4 courses of chemotherapy alone; Group B (n = 33) who received 1 to 5 courses of chemotherapy combined with iodized oil; Group C (n = 23) who received 1 to 3 courses of chemotherapy combined with iodized oil and gelatin sponge; and Group D (n = 12) who received 1 to 3 courses of chemotherapy combined with iodized oil, ethanol and gelatin sponge.The other 57 patients only received liver resection (nonTACE group). The expressions of Ki-67 and proliferating cell nuclear antigen (PCNA) protein were detected in the liver cancer tissues by immunohistochemical method.RESULTS: The Ki-67 protein expression was significantly lower in Groups C and D as compared with non-TACE group (31.35% ± 10.85% vs 44.43% ± 20.70%,30.93% ± 18.10% vs 44.43% ± 20.70%, respectively, P ＜ 0.05). The PCNA protein expression was significantly lower in Groups C and D as compared with non-TACE group (49.61% ± 15.11% vs 62.92% ± 17.21%, 41.16% ± 11.83% vs 62.92% ± 17.21%, respectively, P ＜ 0.05).The Ki-67 protein expression was significantly higher in Group A as compared with non-TACE group (55.44% ± 13.72% vs 44.43% ± 20.70%, P ＜ 0.05). The PCNA protein expression was significantly higher in Groups A and B as compared with non-TACE group (72.22% ± 8.71% vs 62.92% ± 17.21%, 69.91% ± 13.38% vs 62.92% ± 17.21%, respectively, P ＜0.05).CONCLUSION: Preoperative multi-material TACE suppresses the proliferation of HCC cells, while a single material embolization and chemotherapy alone enhance the proliferation of HCC cells.