Hepatitis C virus(HCV)infection is a global public health problem, primarily triggering acute and chronic liver hepatitis. Owing to the narrow host range, a suitable animal model is still lacking, hindering study of viral pathogenesis, immune control,and prophylactic vaccine development. There has no relevant evidence that homologs of HCV originating from the animal may have the potential to cross the species barrier to cause human disease until recently. Several agents discovered that new viruses related to HCV, including HCV and GBV-like viruses(belonging to the Hepacivirus and Pegivirus genera, respectively), in small wild mammals (e.g., rodents and bats)and domesticated animals(e.g., dogs, horses, and cattle). Genetic and biological characterization of these novel HCV-related viruses may provide novel insight into the origins, pathogenesis, and immune response to HCV infection in humans. In this review, we introduce the gene characteristics of HCV, concerned viruses, and many newly discovered viruses closely related to HCV-like viruses. The exploration of their natural reservoirs will be performed, and we then discuss possible theories regarding the origin of this important viral human pathogen.