A method for measuring human CYP3A inducibility upon administration of a test drug, characterized in that a non-human animal to which a test drug is administered or a population of human cells cultured in a medium containing a test drug is infected with viruses (A) and (B); virus (A) being an adenovirus which is used as a vector and engineered by incorporating thereto a detectable reporter gene and at least 3 human PXR binding regions falling within an untranslated region of a human CYP3A gene, and virus (B) being an adenovirus which is used as a vector and engineered by incorporating thereto a human PXR cDNA; and subsequently expression level of the reporter gene is determined in the non-human animal or the cultured human cells.