Objective:To investigate the distribution of common inner ear and internal auditory canal malformations in children with single-sided deafness(SSD) ,and to explore the imaging etiology of SSD by comparing the quantitative parameters of key bone structures between deaf and normal ears in children with congenital SSD. Method:Forty children with SSD diagnosed in the Second Hospital of Lanzhou University from September 2016 to March 2019 were collected. All of them underwent HRCT examinations of temporal bone . The area of bone island, the width of vestibular, the width of internal auditory canal, the height of cochlear and the width of cochlear basal axis were measured. Paired t test was used to compare the difference between the hearing abnormality and normal hearing in children with SSD. Result:The rate of inner ear deformity was 62.5% in SSD group,the most common deformity was cochlear nerve canal deformity, 20 cases (50.0%) of cochlear canal stenosis and 3 cases (7.5%) of cochlear canal atresia.The second most common deformity was internal auditory canal deformity, including 5 cases (12.5%) of internal auditory canal stenosis and 1 case (2.5%) of internal auditory canal atresia. Other malformations included 1 case(2.5%) of RO, 2 cases (5.0%) of incomplete partition (IP) type II and 1 case (2.5%) of enlargement of vestibular aqueduct (EVA). There are no significant difference in the measured results of the key structures of the inner ear between two groups except the width of cochlear nerve canal, internal auditory canal and the area of bone island. Conclusion:The main inner ear deformities in children with SSD are cochlear nerve canal stenosis and inner auditory canal stenosis. HRCT of temporal bone has high diagnostic value for inner ear deformities in children with SSD.