To investigate the possible etiology, clinical characteristics and surgical treatment effects of ossification of the ligamentum flavum of the lower thoracic spine. METHODS: A total of 16 patients with ossification of the ligamentum flavum of the lower thoracic spine, 9 men and 7 women, aged 39 years at the youngest and 75 years at the oldest, with an average age of 51 years, were admitted from April 2002 to April 2007. Site of disease: 2 cases of T10-11 single segment, 2 cases of T11-12 single stage, 8 cases of T10-12 double stage, and 4 cases of T10-L1 three disc levels. The clinical symptoms were diverse, but the sensory localization signs were clear, and the muscle strength of the lower limbs was significantly reduced in 15 cases. The preoperative modified JOA score was 1-3, with a mean score of 2.1. Imaging showed extensive degeneration of the disc in both the lesioned and non-lesioned segments. The results: 1-5 years of follow-up, mean 2 years and 8 months. 16 cases were followed up with total disc decompression, and all were followed up according to the modified JOA score, of which 12 cases were excellent, 2 cases were good, 1 case was acceptable, and 1 case was poor. Conclusion: 1, ossification of the ligamentum flavum of the lower thoracic spine may be related to mechanical and degenerative factors, and the clinical manifestations of spinal cord cone compression caused by it are complex and diverse. 2, Early surgical treatment is the main treatment modality of current treatment.