Background: Surgical site infection (SSI) is a common complication following posterior cervical spine surgery, imposing a high burden on patients and society. However, information about its characteristics and related risk factors is limited. We designed this study intended to address this issue.Methods: From January 2011 through October 2020, a total of 405 patients diagnosed of cervical degenerative diseases (cervical spondylotic myelopathy, ossification of posterior longitudinal ligament and cervical disk herniation) who were treated with unilateral open-door lamnioplasty surgeries were enrolled in this study. We divided the patients into the SSI group and the non-SSI group and compared their patient-specific and procedure-specific factors. Univariate and multiple logistic regression analyses were performed to determine risk factors. Results: There were significant differences between groups in subcutaneous fat thickness (FT) (P<0.001), ratio of subcutaneous FT to muscle thickness (MT) (P<0.001), preoperative Japanese Orthopaedic Association(JOA)Scores (P< 0.003), preoperative serum albumin (P< 0.001), postoperative drainage (P<0.004), time of draining (P<0.001). Logistic regression analysis of these differences showed that ratio of subcutaneous FT/MT, preoperative JOA score, preoperative serum albumin and longer time of draining were significantly related to SSI (P<0.05).Conclusion: Ratio of subcutaneous FT/MT, preoperative JOA score, preoperative serum albumin and longer time of draining are identified as the independent risk factors of SSI in posterior cervical spine surgeries. Identification of these risk factors could be useful in reducing SSI incidence and patients counseling.