Objective To investigate the effects of transcatheter arterial chemoembolization(TACE) on the expression of nm23, tissue inhibitor of metalloproteinase-2 (TIMP-2) and extrahepatic metastasis in hepatocellular carcinoma (HCC). Methods The specimens were collected from resectable HCC in 72 patients. Patients were divided into two groups. In one group, TACE was performed before tumor resection (Group A, n=36). In another group, the tumors were resected directly without preoperative TACE (Group B, n=36). The expression and distribution of nm23, TIMP-2 in the tumor tissue and liver parenchyma in the two groups were compared. All patients were followed up for 24 months,and the incidence of extrahepatic metastasis was compared between the two groups. Chi-square test was applied to compare the expression levels of nm23-H1 and TIMP-2. Results The number of cases of strong, moderate and no expression of nm23 were 24, 6 and 6 cases in group A respectively, and were 9, 6 and 21 cases in group B. Statistical differences were found between the two groups(X~2=15.52, P<0.01). The number of cases of strong, moderate and no expression of TIMP-2 were 21,3 and 12 cases in group A respectively, and were 9, 9 and 18 cases in group B. Statistical differences were demonstrated between them (X~2=9.00, P<0.05). There were 13 cases in group A and 15 cases in group B being diagnosed to have extrahepatic metastasis within 24- month period of follow up, but there was no significant difference between the two groups(X~2= 0.23, P>0.05). Conclusions TACE could enhance the expression of nm23-H1 and TIMP-2 in tumor tissues. Therefore, the potential of metastasis of tumor cells might be prohibited by TACE.