Objective: To evaluate the relationship between the efficiencies of subsegmental TAE and the expression of PCNA with ABC immunohistochemical staining in HCCs. Methods: Ultrasound-guided needle biopsies were performed in 43 patients (41 men, 2 women; age range: 32～75 years, mean, 55.6 years). PCNA were examined using ABC immunohistochemical staining. Tumor scores of PCNA were assessed by counting the positive nuclei per 1,000 cells. All the cases received subsegmental TAE with iodized oil and gelatin sponge. A correlation between the expression of PCNA and the efficiencies of subsegmental TAE was sought. Normality test, rank sum test and Chi-square test were used in statistical analyses with SAS package. Results: The mean PCNA labeling index was 58±29(range, 27-100%) in 43 patients. When compared with the macroscopic and pathologic parameters, PCNA labeling index was found to be significantly related to the presence and activity of cirrhosis. PCNA labeling index did not related to patients age, sex, HbsAg status or serum α-fetoprotein level. The PCNA labeling index corresponded to the degree of histological differentiation (Edmenderson- Steiner grading). The survival rates after subsegmental TAE were respectively 86.05%, 65.12% and 51.16% in one-, two- and three-years, and were significantly higher in the low labeling index group than that in the high labeling index group. Conclusion: The PCNA labeling index was shown to be closely related to histological characteristics and survival of the patients.