Objective To evaluate the feasibility and efficacy of posterior enlargement of spinal canal for the treatment of multi-segmental cervical diseases without cervical lordosis. Methods From January 2013 to June 2017, a retrospective study was conducted with 21 patients of multi-segmental cervical diseases accompanied cervical lordosis loss, and the complete follow-up data was obtained. There were 14 males and 7 females, with an average age of 53.9±7.3 years (range, 42-65 years). There were 14 multi-segmental cervical spondylotic myelopathy, 5 ossification of posterior longitudinal ligament, and 2 congenital cervical stenosis included in this study. The cervical lordotic angle and cervical curvature index were measured preoperatively and 1 year postoperatively. To access the enlargement of spinal canal and spinal cord, the anteroposterior diameter and cross section area of spinal canal or spinal cord were measured on MRI preoperatively and 1 year postoperatively. The Japanese Orthopaedic Association Scores (JOA) was applied to evaluate the neurological function at preoperation and postoperation. Visual Analogue Scales (VAS) was applied to evaluate the pain degree at preoperation and postoperation. Frankel classification was used to assess the severity of spinal cord injury at preoperation and postoperation. Results The follow-up time was 12-26 months, with an average of 16.4 months. The cervical lordosis angle was 3.1°±2.3° preoperatively, and 4.2°±1.6° 1 year postoperatively with a significant difference. The cervical curvature index was 4.4%±1.7% preoperatively and 5.0%±1.5% 1 year postoperatively with no statistically difference. Except for C7T1 level, the preoperative anteroposterior diameter and cross section area of spinal canal at C2,3, C3,4, C4,5, C5,6, and C6,7 level were lower than that at 1 year after operation with a significant difference. Except for C2,3 and C7T1 and level, the preoperative anteroposterior diameter and cross section area of spinal cord at C3,4, C4,5, C5,6, and C6,7 level were significantly lower than that at 1 year after operation. The average JOA score preoperatively was 8.9±1.7. The average JOA score at 3 months postoperatively was 13.1±2.0, which was significantly higher than that preoperatively. At 3 months postoperatively, the average improvement rate was 52.0%, and the superior rate was 52.3%. At 1 year postoperatively, the average JOA score was 13.3±2.1, which improved significantly from that preoperatively. The average improvement rate was 54.3%, and the superior rate was 61.9%. The VAS score at preoperatively was 3.0±2.4, and which was 2.7±1.7 at 1 year postoperatively with no significant differences. At pre-operation, the level of Frankel classification was C level in one (4.8%) case, D level in 8 (38.1%) cases and E level in 12 (57.1%) cases. At 1 year postoperatively, the level of Frankel classification was C level in one (4.8%) case, D level in 6 (28.6%) cases and E level in 14 (66.7%) cases, compared with that at preoperatively, there was no statistically significant difference. One patients suffered from neurologic deterioration at 1 year after surgery and recovered after anterior cervical surgery. No other serious complications were occurred. Conclusion For the patients with multi-segmental cervical diseases accompanied cervical lordosis loss, effective spinal decompression by cervical posterior laminoplasty was feasible, and a good clinical efficacy was achieved. Key words: Cervical vertebrae; Spinal stenosis; Spinal cord compression