Objective To explore the effects of sensory system obstacle on balance ability of patients with hemiplegia after stroke. Methods20 patients with hemiplegia after stroke (experimental group) and 20 normal people (control group) received Sensory Organization Test(SOT) with Smart Equitest Balance Master system. The balance index and the sensory index were accessed. Results The scores of the balanceindex in the experimental group were lower than in the control group in EC, SV, EOSS, ECSS, SVSS (P<0.05). The scores of somatosensory,visual and vestibular indexes in the experimental group were lower than in the control group (P<0.05), especially for vestibular index.Conclusion The sensory loss caused the balance dysfunction in patients with stroke.