Objective:To explore the value of matrix metalloproteinase (MMP) in differential diagnosis of brucellosis spondylitis (BS) and tuberculous spondylitis (TS).Methods:Retrospective analysis was used to collect the data of patients with BS and TS diagnosed in the First Affiliated Hospital of Xinjiang Medical University from January 2016 to December 2018. Magnetic resonance imaging (MRI), laboratory data, and the expression levels of MMP-2 and MMP-9 were analyzed.Results:There existed significant differences in imaging findings like the infection levels, the number of infected vertebrae and the paravertebral soft tissue lesions between BS and TS patients ( n=26, 27, P < 0.05). Basophils in BS patients were significantly higher than those in TS patients [(0.022±0.019) × 10 9 number/L vs (0.017±0.007) × 10 9 number/L, t=2.19, P < 0.05]; but the C-reactive protein of BS patients was significantly lower than that of TS patients [(16.12±14.16) mg/L vs (33.78±24.05) mg/L, t=2.45, P < 0.05]. The expression of MMP-9 in BS patients was significantly lower than that in TS patients [76.92% (20/26) vs 96.30% (26/27), χ 2=4.34, P < 0.05], but there was no significant difference in the expression of MMP-2 ( P > 0.05). Conclusion:MMP-9 may be a new biomarker in differential diagnosis of BS and TS, which can be helpful for the differential diagnosis of BS and TS by combining MRI findings with laboratory findings.