Objective A serum proteomic approach was used to explore the targets of action of Peitu Qingxin Granules(composed of Rhizoma Atractylodis Macrocephalae,Forsythiae Fructus,Imperatae Rhizoma,Pseudostellariae Radix,etc.)in the treatment of atopic dermatitis.Methods Five patients with atopic dermatitis were selected and treated with Peitu Qingxin Granules for 12 weeks,and five healthy volunteers were used as controls.The clinical core evaluation indexes of atopic dermatitis patients after treatment,including Eczema Area and Severity Index/Scoring Atopic Dermatitis(EASI/SCORAD),Pruritus Score,Patient-Oriented Eczema Measure(POEM),and quality of life index,were assessed.Serum samples were examined using data-independent acquisition-mass spectrometry(DIA-MS)technology,and serum differential proteins between atopic dermatitis patients and healthy people,as well as serum differential proteins in atopic dermatitis patients before and after treatment with Peitu Qingxin Granules were screened according to P＜0.05 and Fold Change>1.2.GO function enrichment analysis and KEGG pathway enrichment analysis were performed on the differential proteins.Results(1)Compared with the pre-treatment period,the clinical core evaluation indexes of patients with atopic dermatitis,including the EASI/SCORAD,Pruritus Score,POEM,and quality-of-life index,were significantly improved after treatment,and the differences were all statistically significant(P＜0.05,P＜0.01).(2)A total of 28 differential proteins were analyzed in the healthy control group and atopic dermatitis group,of which 12 proteins expressions were increased and 16 proteins were decreased,including ALAD(δ-aminolevulinic acid dehydrogenase),LTA4H(leukotriene A-4 hydrolase),CA1(carbonic anhydrase 1),F11(coagulation factor XI),and LCP1(lymphocyte cytoplasmic protein 1),etc..The main signaling pathways involved are PI3K-AKT signaling pathway,lipids and atherosclerosis,ECM-receptor interaction,platelet activation,NF-κB signaling pathway,and neutrophil extracellular trap formation.(3)A total of 12 different proteins were analyzed in atopic dermatitis patients before and after treatment with Peitu Qingxin Granules,of which 8 proteins were increased and 4 proteins were decreased,including ALAD,FGA(fibrinogen α-chain),IGHV3-64D,and IGHV3-38.They were mainly involved in signaling pathways such as lipids and atherosclerosis,complement pathway,Staphylococcus aureus infection,NF-κB signaling pathway,fluid shear stress and atherosclerosis.(4)The expressions of three protein targets including ALAD,FGA and IGHV3-64D,were significantly down-regulated in patients with atopic dermatitis and significantly up-regulated after treatment with Peitu Qingxin Granules.Conclusion The differentially expressed proteins ALAD,FGA and IGHV3-64D may be the action targets of Peitu Qingxin Granules in the treatment of atopic dermatitis,which lays the foundation for further experimental validation.