Objective To establish a rat model of middle cerebral artery occlusion (MCAO)by blockage or obstruction of middle cerebral artery. NO precursor L-Arginine (L-ARG) and NO donator Nitroglycerine (NG)are administrated from intraearotid arteries. DWI and PWI are applied to evaluate blood circulation and brain damage of the effected region to elucidate the piotective function of L-ARG and NG in the early stage of brain ischemia. Methods The middle cerebral artery was occluded by insertion of a suture through the internal carotid artery of SD male rats to duplicate ischemia-reperfusion model. Reperfusion was established by suture withdrawal. After 2 hours of blockage, reperfusion and administrate L-ARG,NG by interventional therapy through the internal carotid artery simultaneously. Image indexes such as T1WI, T2WI, DWI and PWI are utilized to assess the changes in different time points. These indexes, Longa score and TTC stain were compared. Results There were obvious decrease in DWI high signal region and Trc pale region in drugs groups, compared with MCAO group(P＜0.01).ADC and rADC values in DWI high signal region increased gradually from 2 hours after ischemia to 24 hours after reperfusion in each group. ADC and rADC values in DWI high signal region of the drugs groups increased obviously(P＜0.01).Conclusion Interventional therapy with NO precursor/donator showed significant protective function in the early stage of brain ischemia.