Objective:This study aimed to evaluate the neuroprotective effect of Buyang-Huanwu Decoction (BYHWD) against cerebral ischemia by using magnetic T2WI and DTI to observe the infarct volume, formation of cerebral edema and injury of white matter fibers on cerebral ischemic rats. Methods:Rat model of cerebral ischemia was established by middle cerebral artery occlusion (MCAO). The successfullly modeled rats were randomly divided into model group and BYHWD group, with 5 rats in each group, and the other 5 rats were taken as sham operation group. The Rats were intragastrically administrated with BYHWD (16.1 g/kg) once daily for 30 d after MCAO. T2WI and DTI examinations were performed on the 3rd, 7th, 14th, 30th day after the surgery.Results:T2WI showed abnormal hyperintensities in the right hemisphere of the MCAO rats on the 3rd, 7th, 14th, 30th day after the surgery. The infarction percentage reduced with time coursing ( P<0.05). Compared with the model group, the rats treated with BYHWD showed reduced infarction percentage [3 d: (13.9% ± 13.7% vs. 40.1% ± 10.7%); 7 d: (13.9% ± 11.9% vs. 28.2% ± 7.7%); 14 d: (10.2% ± 7.9% vs. 24.5% ± 3.5%); 30d: (6.8% ± 6.5% vs. 24.7% ± 8.7%)] ( P<0.05 or P<0.01). The percentage of edema reached the peak on the 3rd day after MCAO. Due to the cerebral atrophy on 30th day, the percentage of edema exhibited negative growth. The edema percentage of BYHWD group reduced significantly on the 3rd and 7th day compared with model group [3 d: (11.4% ± 6.9% vs. 21.5% ± 3.1%); 7 d: (5.5% ± 3.1% vs. 8.7% ± 1.2%)] ( P<0.05 or P<0.01). DTI showed that the low signals indicating fiber injuries were observed in the infarct areas of the model group rats on the 3rd, 7th, 14th, 30th day after MCAO. The rFA values in the ipsilateral cortex and striatum of MCAO rats were significantly decreased compared with the sham group ( P<0.05 or P<0.01). The rFA values in cortex and striatum in focal cerebral ischemia rats of BYHWD group were higher than those in the model group, while only 14 d showed significance ( P<0.05 or P<0.01). Conclusions:T2WI and DTI clearly provided the informations of the location and morphology of the infarct areas. The ischemic brain showed significant infarction, edema, and white matter injury, which were ameliorated with time going on. BYHWD reduced the infarction percentage, inhibited cerebral edema and stimulated the recovery of neurofibra, suggesting that BYHWD could protect against cerebral ischemia.