This study aimed to perform a systematic proteomic analysis of serum samples from patients with idiopathic membranous nephropathy (IMN) and healthy controls using label-free quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS). The goal was to identify differentially expressed proteins associated with IMN, explore potential pathogenesis, and screen candidate biomarkers. All serum samples were processed following standard protocols and analyzed using a Thermo Scientific Q-Exactive HF-X mass spectrometer operated in data-dependent acquisition (DDA) mode. Raw data were processed with MaxQuant and searched against the UniProt human protein database for identification and quantification. Differentially expressed proteins were subjected to functional annotation (GO) and pathway enrichment analysis (KEGG). Key findings were further validated using parallel reaction monitoring (PRM). This dataset provides a systematic serum proteomic resource for understanding the molecular mechanisms of IMN.