The present invention is related to a transgenic animal inducing Alzheimer's disease. More particularly, the present invention is a vector for transformation of animal comprising a carboxyl-terminal fragments of mutant human beta amyloid protein which contains Indiana mutation (.beta.CTF99) and a transgenic mouse inducing Alzheimer's disease prepared by microinjection of the same into a pronuclei of a fertilized oocyte. The transgenic mouse of the present invention exhibited clinical symptoms of Alzheimer's disease such as decreased of cognitive ability and memory, and increases of anxiety. Therefore, the transgenic mouse of the present invention will be useful animal model for a research of Alzheimer's disease. Particularly, since the transgenic mouse of the present invention showed more remarkable decreases of cognitive ability than any other transgenic animal model for Alzheimer's disease known in the art, the transgenic mouse of the present invention can be used as an animal model for disease relating anxiety.