Grazoprevir, an HCV nonstructural protein 3/4A (NS3/4A) inhibitor 100 mg, plus elbasvir, an HCV NS5A inhibitor 50 mg fixed dose combination, Zepatier, achieved high SVR12 rates of > 95 % in treatment-naïve, experienced cirrhotic and non-cirrhotic patients with genotype 1, 4, or 6 infection. Zepatier, 12 to 16 weeks, was approved for the treatment of HCV genotype 1 and 4 in Taiwan in December, 2016. An SVR rate of 93 % was demonstrated in treatment-naive, non-cirrhotic (F0-F3) GT1b-infected patients who received 8 weeks of grazoprevir/elbasvir with or without ribavirin in the pooled analysis of C-WORTHY (PN035) and C-EDGE treatment-naive (PN060) trials. Furthermore, truncated treatment period of 8-week grazoprevir/elbasvir could achieve an even higher SVR rate at > 98% for naive HCV G1b patients with mild fibrosis (Fibrosis score 0-2). The study aims to evaluate the efficacy of 8-week regimen with grazoprevir/elbasvir on naïve, HCV G1b patients with mild fibrosis by a randomized clinical trial.