Abstract:[Objective] To explore the effect of selective posterior rhizotomy (SPR) on the hip development in children with spastic ce- rebral palsy. [Methods] A retrospective study was performed on 50 children (100 hips) who underwent SPR for spastic cerebral palsy in our department from February 2017 to February 2020. The patients were divided into preschool group and school age group according to the age at operation. The clinical and imaging results of the two groups were compared. [Results] All children in both groups had operation per- formed successfully without serious complications. The preschool group consumed significantly less operative time with significantly less in- traoperative blood loss than the school age group (P<0.05) . The children were followed up from 2 to 3 years, with an average of (2.52±0.43) years. The score of Gross Motor Function Measure (GMFM) 88-E, hip flexor-extension and adduction-abduction ROMs, as well as Ash- worth muscle tone scales and MRC scale for hip muscle strength significantly improved at the latest follow-up compared with those preoper- atively in both groups (P<0.05) . However, there were no statistically significant differences in the abovementioned clinical items between the two groups at any corresponding time points (P>0.05) . Radiographically, compared with those preoperatively the acetabular index (AI) and neck shaft angle (NSA) had not significantly changed in both groups at the latest follow-up (P<0.05) ; the center-edge (CE) angle in the preschool group increased significantly (P<0.05) , whereas which remained unchanged in school-age group (P<0.05) ; the migration per- centage (MP) of femoral head significantly decreased in both groups at the latest follow up (P<0.05) . Comparison between the two groups before operation showed that the AI, MP and NSA of preschool group were significantly higher (P<0.05) , and the CE angle significantly low- er than those of school-age group (P<0.05) . Despite of the facts that the preschool group still had significantly greater AI and NSA, where- as significantly less CE angle than the school-age group (P<0.05) , there was no significant difference in MP between the two groups at the latest follow up (P>0.05) . [Conclusion] Lumbosacral SPR can improve the development of hip joint in children with spastic cerebral palsy.