Objective This study aims to analyze the proteomic characteristics of peripheral blood in patients with lung cancer coexistent with pulmonary tuberculosis(LC-PTB),identify the differential proteins compared with lung cancer(LC)patients,and conduct functional analysis on these proteins.Methods The study included 8 LC-PTB patients and 10 LC patients.The LC patients were newly diagnosed and confirmed by pathology and did not receive any anti-tumor treatment before,while the PTB patients were Mycobacterium tuberculosis positive at the time of sampling.Liquid chromatography-tandem mass spectrometry(LC-MS/MS)was applied to perform proteomic mass spectrometry to assess the differential proteins,and then functional analysis was conducted via bioinformatics.Results A total of 5,185 proteins were detected between two groups.Through differential expression screening,190 proteins(58 upregulated and 132 downregulated)were identified to be differentially expressed.Subcellular localization analysis revealed that the differential proteins were mainly concentrated in the cytoplasm,nucleus,and extracellular matrix.KEGG pathway and GO analysis showed the roles of differential proteins in biological processes including immune response,metabolism,and secretion regulation.Protein interaction network analysis highlighted the importance of SORT1,SAR1B,RPS6KB1,VWF,SHC1,SRPRB,CTSD,TARDBP,RPLP0,PSMA2,RPS6,XPO1,PRKACB,and HLA-DRB1 in LC-PTB.Additionally,the expression changes in proteins like ADA2,MAP3K1,and GLS2 might be closely associated with the development of LC-PTB.Conclusions The proteomic profile comprehensively described the proteomic characteristics of LC-PTB and identified numerous differentially expressed proteins,which could provide further clues for research on biological mechanism of LC-PTB.