Objective To improve efficacy of treatment of the cerviacl spondylosis myelopathy and to avoid misplay during operation.Methods The mistherapy reasons for 10 cases of CSM were retrospectively analyzed.All the 10 cases were operated with expansive open door laminoplasty of cervical spine,nine of which had been followed up for from 2 weeks to 8 months.Results Satisfactory results were obtained among the DCS(6 cases) and OPLL(3 cases),with an average JOA recovery rate being 63.53% and 73.66% respectively.Three reasons were among the displays:①Inadequate range of open door laminoplasty of cervical spine of from C 3 to C 5 rather than from C 3 to C 7.② Incomplete decompression of continuous type ,the segmental type and surgical excision through anterior cervical spine among the CSM accompanied by OPLL with the potential danger of injury of spinal cord at the same time.③The cervical spondylosis radiculopathy being not suitable to open door laminoplasty.Conclusion It was key factors to choose indication correctly and perform the operation seriously if less display and improved efficacy were expected.