【Objective】To investigatethe correlation between blood flow signal on three dimensional time-of-flight magnetic resonance angiography（3D-TOF-MRA）and short-term outcome in patients with symptomatic middle cerebral artery（MCA）severe stenosis or MCA occlusion.【Methods】We retrospectively reviewed consecutive patients with symp? tomatic MCA severe stenosis or MCA occlusion. General information，clinical data and cranial imaging data were collect? ed. Characteristics of blood flow signal on 3D-TOF-MRA for each patient were analyzed，which included：（1）blood flow signal of MCA distal to stenosis/occlusion lesion；（2）laterality of posterior cerebral artery（PCA）. The correlation between characteristics of blood flow signal and short-term outcome was analyzed.【Results】Three hundred and twenty-eight patients were included in this study. There were 154 patients with symptomatic MCA severe stenosis and the rest of them had symptomatic MCA occlusion. Poor blood flow signal of distal MCA independently correlated with poor short- term outcome in patients with severe MCA stenosis.［Odds Ratio（OR）0.32，95% Confident Interval（CI）0.14~0.72］. PCA laterality was not related with short-term outcome in these patients（OR，2.28，95% CI，0.85~6.15）. PCA laterality independently correlated with poor short-term outcome in patients with MCA occlusion.（OR，3.54，95% CI，1.32~ 9.78）. Blood flow signal of distal MCA was not related with short-term outcome in these patients（OR，0.58，95% CI， 0.22~1.48）.【Conclusion】Blood flow signal on 3D-TOF-MRA correlates with short-term outcome in patients with symptomatic MCA severe stenosis or occlusion but the characteristics differs between severe MCA stenosis and occlusion patients. Anterograde blood flow（blood flow signal of MCA distal to stenosis lesion）for patients with severe MCA stenosis and retrograde blood flow（PCA laterality）for patients with MCA occlusion correlates with shot-term outcome.