Abstract: OBJECTIVE To explore the correlation of proalbumin (PA), serumamyloid A (SAA), CD64 and soluble leukocyte differentiation antigen 14 subtype (s CD14-ST) with acute respiratory tract infection in children and its diagnostic value. METHODS A total of 498 children with acute respiratory tract infection admitted to pediatrics department of Meishan City People's Hospital from Jan 2019 to Dec 2022 were enrolled as the study group. According to the results of bacterial culture of throat swabs, the children were divided into the bacterial infection group (232 cases) and the non-bacterial infection group (266 cases). A total of 506 healthy children in the same period were recruited as the control group. Serum levels of PA, SAA and peripheral blood sCD14-ST and CD64 index were detected by automatic biochemical analyzer, latex enhanced immunoturbidimetry, flow cytometry and chemiluminescence, respectively. Clinical data of each group were analyzed, serum levels of PA, SAA and peripheral blood sCD14-ST and CD64 index were compared among the groups. The diagnostic value of serum levels of PA, SAA and peripheral blood sCD14-ST and CD64 index individual and combined detection in children with acute respiratory tract infection was analyzed by operating characteristic curve (ROC) analysis. RESULTS The serum level of PA in the control group was higher than that in the non-bacterial infection group and bacterial infection group (P＜0.05); and that in the bacterial infection group was lower than that in the non-bacterial infection group (P＜0.05). The serum levels of SAA and sCD14-ST and CD64 index in peripheral blood of the control group were lower than those of the non-bacterial infection group and bacterial infection group (P＜0.05), while those of the bacterial infection group were higher than those of the non-bacterial infection group (P＜0.05). ROC curve analysis showed the ara under curve (AUC) of combined detection of serum PA, SAA, peripheral blood sCD14-ST and CD64 index in the diagnosis of children with acute respiratory tract infection was 0.934, which was higher than that of the individual detection (P＜0.05); and the sensitivity and specificity of combined detection were 89.20% and 81.40%, respectively, indicating high diagnostic value. CONCLUSION The level of serum PA is low in children with acute respiratory tract infection, while the level of serum SAA, peripheral blood sCD14-ST and CD64 index are high. And these indexes further decrease or increase after infection. The combined detection of serum PA, SAA, peripheral blood sCD14-ST and CD64 index is helpful for the diagnosis of acute respiratory tract infection in children.