Objective To explore the predictive value of serum amyloid A (SAA) combined with interleukin-6 (IL-6) and C-reactive protein/albumin ratio (CRP/ALB) for intravenous immunoglobulin (IVIG) reactivity in children with Kawasaki disease (KD). Methods A total of 120 children with KD (disease course ≤5d) who were treated with aspirin combined with IVIG in the hospital were retrospectively enrolled from March 2021 to March 2024. According to IVIG reactivity, they were divided into reactivity group (n=94) and non-reactivity group (n=26). The clinical characteristics and laboratory data in the two groups were collected, and influencing factors of IVIG reactivity were analyzed by univariate and multivariate analysis. Predictive value of SAA combined with IL-6 and CRP/ALB for IVIG reactivity was analyzed by receiver operating characteristic (ROC) curves. Results The fever duration in reactivity group was longer than that in non-reactivity group (P＜0.05). Before treatment, levels of PLT, CRP, AST, ALT, SAA, IL-6 and CRP/ALB in non-reactivity group were higher than those in reactivity group (P＜0.05). The results of multivariate Logistic regression analysis showed that long fever duration was an independent protective factor of IVIG reactivity, while high levels of CRP, SAA, IL-6 and CRP/ALB were independent risk factors (P＜0.05). The results of ROC curves analysis showed that SAA, IL-6 and CRP/ALB were all of predictive value for IVIG reactivity (AUC=0.883, 0.702, 0.735, P＜0.05), and predictive value of combined detection was higher (AUC=0.933, P＜0.05). Conclusion The increased levels of SAA, IL-6 and CRP/ALB are independent risk factors of IVIG non-reactivity in KD children. All the three indexes have predictive value for IVIG reactivity, and predictive value of combined detection is higher