Objective:To investigate the risk factors of sacroiliac joint damage in patients with juvenile-onset spondyloarthropathy(JSpA),and to provide reference for the selection of appropriate treatment strategy. Methods:To analysis the clinical data of 212 cases of JSpA,including demographic factors(sex,age),genetic factors,the affected area,laboratories indicators. Patients were divided into two groups according to age (≤ 11 years old and 12~16 years old). Using the Logistic regression to filter out the risk factors of sacroiliac joint damage in patients with JSpA. Results:Out of the 212 cases,124(58.5%) patients suffered from sacroiliac joint damage. Single factor analysis showed that a number of factors were related to sacroiliac joint damage. Logistic regression analysis showed that the course of disease,at the onset of peripheral arthritis,particularly the large joints of lower limbs,tendon-sustained inflammation and HLA-B27-positive,family history were the risk factors of sacroiliac joint damage. Conclusion:The incidence of sacroiliac joint damage in JSpA patients is high and it is associated with multiple factors. For patients with these risk factors,early intervention and MRI examination of sacroiliac joint regularly should be taken to reduce or delay the disease progression.