Abstract： Objective To evaluate the efficacy of autologous eytokine-induced killer cells (CIKs) infusion after transcatheter arterial chemoembelization (TACE) combined with radiofrequency ablation (RFA) for patients with small hepatocellular carcinoma (SHCC) and the immunologic index changes of patients with SHCC after CIKs adoptive immunotherapy. Methods Forty-three patients with SHCC in our hospital from February 2004 to February 2006 were recruited and were divided into two groups after receiving TACE and CT-guided RFA. The study group (21 cases) received autologous CIKs infusion more than 4 times, and the number of CIKs infused ranged from 1.1×1010 to 1.5×1010 every time. The control group (22 cases) only received TACE combined with RFA. The levels of T lymphocyte subsets and native killer (NK) cells in peripheral blood of patients with SHCC in study group before and after CIKs infusion were detected. All the patients in both groups were evaluated every 1 to 2 months during follow-up. Results (1) 1-, 2-and 3-year intrabepatic accumulative recurrence rates in study group were 9.5%, 14.3% and 19.0% respectively, and those in control group were 9.1%, 22.3%and 27.3% respectively. 1-, 2- and 3-year survival rates in study group were 95.2%, 85. 7% and 76.2% respectively, and those in control group were 95.5%, 81.8% and 68.2% respectively (P=0.558). (2)The percentages of CD3+, CD4+ and CD56+ effect cells and the proportion of CD4+/CD8+ were obviously increased after CIKs infusion (P<0.05) ; while the percentages of CD8+ and CD3+CD56+ effect cells were decreased in study group(P<0.05). Conclusion Sequential CIKs infusion after TACE combined with RFA can improve immune function of patients with SHCC, and may play an important role in reducing recurrence rate of SHCC and prolonging the survival time.