Abstract:[Objective] To compare the general bone mineral density (BMD) and local bone structure around the lesion between spinal tuberculosis (STB) and pyogenic spondylitis (PS) . [Methods] A total of 36 patients who received surgical treatment for spinal bone destruc- tion secondary to infection in the Department of Spine Surgery, Xiangya Hospital, Central South University were enrolled into this study, and divided into spinal tuberculosis (STB) group and pyrogenic spondylitis (PS) group based on the consequence of microbiologic assays. The two groups were paired according to gender, and were compared in terms of the preoperative general BMD, CT grayscales of affected vertebra and adjacent vertebra. In addition, the bone volume/tissue volume (BV/TV) , thickness of trabecular bone (Tb.Th) and sparse densi- ty of trabecular (Tb.Sp) measured on the trabecular bone around the lesion taken out during the operation by micro-CT were compared be- tween the two group. [Results] There were no significant differences between STB group and PS group in terms of the BMDs of the total lum- bar, cervical vertebra, femoral intertrochanteric area and the Ward triangle (P>0.05) , neither in BMDs of aforesaid areas between the Gram-positive subgroup and Gram-negative subgroup of the PS patients (P>0.05) . The STB group had significantly higher CT grayscales than the PS group (P<0.05) . The CT grayscales of sclerosed bone around lesions in both groups significantly increased (P<0.05) , which in STB group was significantly higher than the PS group (P<0.05) . In term of micro-CT, the STB group got significantly higher BV/TV and TB. Th, whereas significantly lower Tb.Sp than the PS group (P<0.05) . [Conclusion] The STB has more vigorous pathological osteogenesis around lesions than the PS, with increase of density and thickness of local bone trabeculae, however, there was no significant difference in general BMD between the two groups.