Abstract: Abstract Objective:To investigate the clinical characteristics and risk factors of Kawasaki disease (KD) complicated with hip joint synovitis(SH). Methods:The children admitted to the KD database of Yuying Children's Hospital Affiliated to Wenzhou Medical University from January 1st, 2013 to May 1st, 2017 were reviewed. The case group was children with SH(SHKD group) and the control group was children without SH (KD group). The possible risk factors of SH in children with KD were analyzed. Results:A total of 1,038 children with KD were included in this study, 13 in SHKD group and 1,025 in KD group. In 13 cases of SHKD, there were 6 males and 7 females, the average age of onset was (35.5 ± 15.3) months, and synovitis appeared on the 1st to 17th (9.1 ± 4.2) day. There were 9 cases of bilateral SH, 2 cases of right SH, 1 case of left SH and 1 case of synovitis of hip and knee joint. After treatment with intravenous immunoglobulin (IVIG) and aspirin, coronary artery lesion (CAL) occurred in 1 case, shock occurred in 1 case, and IVIG-resistance occurred in 3 cases. The recovery time of SH symptoms was 1-10 (4.0 ± 2.4) days. Age, D-Dimer and the incidence of IVIG-resistance were statistically significant between the two groups (P-value was 0.026, 0.003 and 0.012, respectively). Multivariate logistic regression analysis found that the increase of D-Dimer and IVIG-resistance were independent risk factors for SHKD, and OR was 1.151 (95%CI：1.021-1.297) and 12.239 (95%CI：2.476-60.485), respectively. Conclusion:The clinical manifestations of SHKD were mainly hip joint pain and limited lower limb activity, with mild symptoms and a good prognosis. The increase in D-Dimer and IVIG-resistance were independent risk factors for SHKD.