Abstract: Objective To investigate the relevance between relapse and course of treatment in genotype 1 chronic hepatitis C( CHC) patients with slow virologic response. Methods Totally 157 genotype 1 CHC inpatients or outpatients were selected from the Third People' s Hospital of Jiaozuo and the People's Hospital of Jiaozuo from April 2010 to March 2013. The patients were treated with interferon α- 1b in conjunction with ribavirin. At 6 months of the initial treatment,51 patients with slow virologic response were randomly divided into groups A( 24 cases) and B( 27 cases),which received continued treatment for another 6 and 12 months,respectively. A 1- year follow- up of patients was performed after withdrawal of treatment. Adverse reactions in patients receiving the antiviral therapy were assessed. Furthermore,group comparisons were performed on the clearance rate of hepatitis C virus( HCV) RNA and normalization rate of alanine aminotransferase( ALT) at withdrawal of treatment,as well as the CHC relapse rate and ALT normalization rate at 6 months and 1 year after withdrawal of treatment. Continuous data were compared using t test,and categorical data were compared using χ2test. Results The rate of adverse reactions in patients receiving antiviral therapy had no significant difference between groups A and B( P > 0. 05). At withdrawal of treatment,there were no significant differences between groups in terms of HCV RNA clearance rate( 95. 65% vs 92. 59%) and ALT normalization rate( 95. 65% vs 88. 89%)( χ2= 0. 02 and 0. 13,respectively,both P > 0. 05). At 6 months and 1 year after withdrawal of treatment,the CHC relapse rate in group B was significantly lower than that in group A( 20. 00% vs 50. 00%,χ2= 4. 69,P < 0. 05; 36. 00% vs68. 18%,χ2= 4. 85,P < 0. 05); the ALT normalization rate in group B was nonsignificantly higher than that in group A( 84. 00% vs59. 09%,χ2= 3. 63,P > 0. 05; 72. 00% vs 50. 00%,χ2= 2. 40,P > 0. 05). Conclusion To extend the 6- month course of treatment can significantly reduce the relapse following slow virologic response in patients with genotype 1 CHC.