Abstract: Objective: To investigate the clinical outcome and indication of one stage combined anterior-posterior decompression for severe cervical spondylotic myelopathy (CSM).Methods: Retrospective analysis of 12 cases with severe CSM were performed one stage combined anterior-posterior decompression.Japanese Orthopedic Association (JOA) score system and the clinical outcome were used to evaluate the neural function.The improvement rate and clinical curative effect were evaluated.Results: The surgical time was 2.5-5 hours,blood loss was 480-1 200 ml.No severe intraoperative complication was noted except cerebrospinal fluid leakage in 2 cases.All cases were followed up from 6 months to 4 years,both anterior grafts and posterior door axial had bony union.All cases had excellent neural function improve rate.MRI showed dural cyst moved dorsally and decompression in all cases,CT showed the spinal canal was enlarged sufficiently and the average angle of open-door was 45.2°.Conclusions: When patients with complex multi segmental CSM are carefully selected and surgery is indicated,the one-stage combined anterior-posterior decompression approach can achieve good short-term clinical effect.