The present invention relates to a method for producing virus-infected cell line or animal model. According to the present invention, for a human-derived lipid layer of a virus, a bile acid or a bile acid derivative allows the lipid layer to be replaced with a target animal model-derived lipid layer; and this makes it possible to produce a virus-infected animal model that can be effectively used clinically without limitation resulting from species specificity. Furthermore, in the method for producing a cell line, viruses are mixed with a bile acid or a bile acid derivative and the mixture is used to treat a culture medium of a cell line, so that a cell line infected with a very high level of the viruses can be obtained. In addition, use of the method for producing a cell line of the present invention allows viruses to infect cell lines derived from various species and organs without limitation resulting from the viral species specificity and the restraining force related to the viral specific tissue or organ tropism.