An object of the present invention is to provide a method for introducing a gene into an embryo for production of a human disease model primate animal using a non-human primate animal such as a marmoset. The present invention relates to a method for introducing a foreign gene into an early embryo of a non-human primate animal, which comprises placing early embryos of a non-human primate in a 0.2 M to 0.3 M sucrose solution, so as to increase the volume of the perivitelline spaces, and then injecting a viral vector containing a human foreign gene operably linked to a promoter into the perivitelline spaces of the early embryos.