Abstract： Objective To study the tissue growth of embryonic brain grafts in monkey.Methods Embryonic brain tissue transplantation was performed on 10 monkeys who were divided into immediate transplanted group and delayed transplanted group.The grafts was the embryonic tissue homogenate and transplanted into the wound.Results The behaviors and body temperature in the monkeys after transplantation were normal.Histologically,it was found that part neurons was survival in the host brain one month after transplantation.Three months later,retrograde degeneration of the neurons was found and part neurons vanished.Six months after transplantation,only neuron degeneration scar-tissue colloid and the phagocyte infiltration were seen in the transplant area.However,a monkey was found to have the neuIDn survival and the connection of neurofibrils between the grafts and host cerebral cortex.Conclusion Allotransplantation might have severe rejection.The survival of the transplants in immediate transplantation and delayed transplantation had no significant difference.