Abstract:BY the systematic anatomical observation of the uniting process of walnut grafting branch, the results indicate that the uniting process of walnut grafting branch consists of 5 stages: non-formation of callus, callus initiation, callus junction between stock and scion, cambium differentiation and union, vascullar tissue differentiation and union. Meanwhile, the main factors affecting the uniting process of walnut grafting branch were analysed and discussed.