Effect of aluminum on neurobehavior and the number of neurons in different domains of brain as well as granulovacuolar degeneration (GVD) in hippocampus were observed in Sprague-Dawley rats by intraperitoneal injection with aluminum chloride for 60d. The injection of aluminum at the dosage of 4.0 or 10.0 mg/kg could decrease active avoidance response and spontaneous motor activity in the shuttle-box test and the open field test significantly. Sections from cerebrum, cerebellum and hippocampus were detected with microscope after HE staining. Aluminum(10.0 mg/kg) could result in the decrease of neurons in cerebrum, Pukinje cells in cerebellum and pyramidal neurons in hippocampus. GVD of nerve cells in hippocampus were observed in each group, while the dosages of Al injected was 4.0 and 10.0 mg/kg, the number of GVD cells increased significantly. The incidence of GVD per 300 nerve cells was significantly related to the dosage of aluminum.