Objective: To investigate the safety and efficacy of applying ultrasonic osteotome in patients undergoning cervical expansive open-door laminoplasty (CEOL).Methods:In the study , 94 consecutive patients who were administrated in the spine group of Orthopedic Department of Peking University Third Hospital from March 2015 to March 2016 were reviewed retrospectively. All the patients were diagnosed as multilevel cervical spondylosis myelopathy and underwent CEOL. These patients were divided into two groups: ultrasonic osteotome group and traditional group, by whether the ultrasonic osteotome device was used in operation. The parameters we studied were as follows: the duration of operation, blood loss in operation, volume of drainage on the first postoperative day, days of remaining the drainage tube, preoperative and postoperative Japanese Orthopedic Association (JOA) scores, complications of cerebrospinal fluid leak and hinge bone nonunion.Results:Compared with the traditional group, the duration of operation of the ultrasonic osteotome group was increased, but the blood loss in operation, volume of drainage on the 1st postoperative day and days of remaining the drainage tube of the ultrasonic osteotome group were all reduced. There was no obvious difference between the two groups when considering the cerebrospinal fluid leak. At the end of the 3-month follow-up, the JOA score and improvement rate of the JOA score were of no obvious difference between the two groups. But the hinge bone union of the traditional group was better than the ultrasonic osteotome group. At the end of the 12-month follow-up, all the JOA score, the improvement rate of the JOA score and the hinge bone union were not obviously different between the two groups.Conclusion:Applying ultrasonic osteotome in patients undergoing cervical expansive open-door laminoplasty is both safe and effective. Compared with the rongeur, ultrasonic osteotome can cause the delayed union of the hinge bone, but it reduces the blood loss in operation, volume of postoperative drainage and days of remaining the drainage tube.