Objective To explore the diagnostic values for large vestibular aqueduct syndrome by MRI. Methods 26 cases of patients with children with large vestibular aqueduct syndrome were researched, the CT and MRI results were compared. Results High resolution computed tomography (CT) images is enlarged vestibular aqueduct different level and different shapes of bone defect in the shadow, VR 3D images after restructuring visible in vestibular aqueduct expand; MRI image visible expand different level within the lymph sac and lymphatic vessels, all show high signal, VR after restructuring lymph sac expand inside seen in 3D images. There has no significant difference on the results of vestibular aqueduct related ministries and measurement(P ＞0.05). Conclusion Magnetic resonance imaging (MRI) and high resolution CT can expand visual display vestibular aqueduct, vestibular aqueduct and high resolution CT is more focused on the expansion of osseous structure shows that while MRI within lymph sac expands as the main display results, both for large vestibular aqueduct syndrome have accurate diagnosis effect.