This is randomized double-blind placebo-controlled trial that will be conducted in referral teaching hospitals in Taiwan. This trial will recruit 320 patients fulfilling all of the following criteria: patients more than 20 years old, HCCs diagnosed by AASLD image criteria or pathology, medium-sized HCCs in BCLC intermediate stage and not more than 5 cm in maximum diameter and not more than 5 tumors that TACE is indicated, chronic HBV carrier (HBsAg+) with detectable HBV DNA in blood, ECOG performance status (PST) 0-2, Child-Pugh score ≦7, serum bilirubin < 2 mg/dL and prothrombin time (PT) prolongation < 3 seconds, and willingness to adhere to treatment and follow-up plans. Patients are ineligible if they have any of the following exclusion criteria: any vascular invasion by tumors, extra-hepatic metastasis, concurrent any other malignancy, concomitant immunosuppressive therapy, previous any HCC treatment, previous or current any antiviral therapy for HBV, concomitant other therapies for HCC except TACE, liver cirrhosis with severe gastroesophageal varices (EVF3 or with red color sign), poorly-controlled ascites or hepatic encephalopathy, contraindication for invasive procedures such as recent gastrointestinal bleeding or cerebral hemorrhage, contraindication to TACE such as allergy to contrast, pregnancy, sepsis, etc., chronic renal failure with eGFR < 60, concurrent any other chronic viral hepatitis with HCV, HDV, or HIV). The Primary endpoints of this study will be 1-, 3-year overall survival, and the secondary endpoints of this study will be time to tumor progression and time to liver decompensation.