PROBLEM TO BE SOLVED: To provide an anti-HCV agent.SOLUTION: The present invention provides an anti-HCV agent comprising guanfacine or salt thereof, a method of inhibiting the replication of HCV using the anti-HCV agent, and a composition for treating or preventing hepatitis C that comprises guanfacine or salt thereof or the anti-HCV agent, and a kit comprising the composition.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】抗HCV剤の提供。【解決手段】グアンファシン又はその塩を含む抗HCV剤、該抗HCV剤を用いてHCVの複製を抑制する方法、並びにグアンファシン若しくはその塩又は該抗HCV剤を含むC型肝炎の治療若しくは予防用組成物、及び該組成物を含むキット。【選択図】図1