Objective To explore the differentially expressed genes (DEGs) related to ankylosing spondylitis (AS) through bioinformatics strategies,and to find new diagnostic markers for the disease.Methods The microarray data related to AS were downloaded from the Gene Expression Omnibus (GEO) database of the National Center of Biotechnology Information,and the DEGs between the AS patients and healthy population in the peripheral blood were analyzed and screened.The Database for Annovation,Visualization,and Integrated Discovery (DAVID) was used to complete the Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analyses of the DEGs,and then the online database String was used to construct a protein-protein interaction (PPI) network,and the Cytoscape 3.7.1 software was used to screen the significant protein modules in the PPI network to obtain hub genes.The area under curve (AUC) values of the receiver operating characteristic (ROC) curves were calculated to evaluate the diagnostic efficacy of hub genes for AS.Results A total of 187 DEGs were screened out,including 96 up-regulated genes and 91 down-regulated genes.The results of GO function analysis showed that the DEGs were mainly involved in ribonucleoside monophosphate metabolism process,nucleoside monophosphate metabolism process and purine ribonucleoside monophosphate metabolism process.And the results of KEGG signaling pathway analysis showed that DEGs mainly participated in non-alcoholic fatty liver disease,Huntington's disease and oxidative phosphorylation.Five hub genes (adenosine triphosphate synthase,H⁺ transporting,mitochondrial F0 complex,subunit F6[ATP5J],NADH:ubiquinone oxidoreductase subunit B3[NDUFB3],ubiquinol-cytochrome c reductase binding protein[UQCRB],cytochrome c oxidase subunit 7A2[COX7A2],and ubiquinol-cytochrome c reductase hinge protein[UQCRH]) were screened out based on the results of PPI network analysis,showing significant diagnostic efficacy for AS (AUC values were 0.859,0.852,0.840,0.820,and 0.805,respectively).Conclusion ATP5J,NDUFB3,UQCRB,COX7A2 and UQCRH may be used as new diagnostic markers related to AS in peripheral blood.