Abstract: Alzheimer disease（AD） is a type of primary brain neurological disease with unknown etiology. It is characterized by senile plaques and nerve fiber tangles, and has been a serious threat to human health. The establishment of an ideal animal model of AD, to research on AD pathogenesis, AD screening and prevention of new drugs is essential. β-amyloid precursor protein（APP） gene was integrated into the C57 BL/6 J mice（Mus musculus） genome, and the hippocampus of mice were taken after twenty weeks. immunoprecipitation and immunohistochemical results showed amyloid precursor protein expression, Y maze detection result showed transgenic mice got worse memory, and decreased by 18% compared with the blank control group. The establishment of Alzheimer disease transgenic mouse model provides a good foundation to further AD disease research.