To elucidate the MR urography (MRU) features of ectopic ureter orifice in children and to explicate its advantages, the clinical data and MRU findings of 4 cases with ectopic ureter orifice were analyzed retrospectively. Among the 4 cases of ectopic ureter orifice, 2 were associated with dysplasia of kidneys, 1 was associated with duplex kidney, and the remaining 1 was associated with cross ectopic and dyplasia kidney. When combining the MRI and MRU examination, we could diagnose the ectopic orifice of the draining ureters. So we concluded that definitive diagnosis could be achieved in most of the cases by integrating clinical information with MRU findings.