Background Post–traumatic stress disorder (PTSD) is characterized by impaired fear extinction, excessive anxiety and depression. However, underlying mechanisms, especially the function roles of long non–coding RNAs (lncRNAs) involved in PTSD is still unclear. We argued that the lncRNAs, co–expressed mRNAs, as well as the associated pathways, are altered and may thus serve as potential biomarkers and key pathways related to PTSD.Methods The gene expression profiles of GSE68077 was downloaded from the GEO database, and the differentially expressed lncRNAs and mRNAs were identified. Gene ontology (GO) and Kyto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis were performed. Subsequently, protein–protein interaction (PPI) network was analyzed, and module analysis of the differentially expressed mRNAs was performed with Cytoscape software. Finally, lncRNAs–mRNAs co–expression network was constructed and core pair lncRNAs involved in PTSD were mapped.Results A total of 45 differentially expressed lncRNAs and 726 differentially expressed mRNAs were obtained. Among of which, 17 lncRNAs and 86 mRNAs were inter–regulated, and most of the lncRNAs–mRNAs co–expression showed positive correlations. The lncRNAs–mRNAs co–expressed network suggested the potentially functional roles of lncRNAs, regulated mRNAs and related pathways in PTSD. By implication of the core pair network, lncRNA–NONMMUT010120.2 synergistically up–regulated Ppargc1a and down–regulated Cir1, Slc38a9, Atp6v0a2. Moreover, lncRNA–NONMMUT023440.2, NONMMUT034155.2, NONMMUT105407.1 and NONMMUT149972.1 were co–expressed with 10 co–expressed mRNAs, which indicated that lncRNAs involved in PTSD might work by regulating the co–expressed mRNAs.