Objective:To screen differentially expressed circular RNA (circRNA) in rat articular chondrocyte injury induced by T-2 toxin, and explore the mechanism of cartilage injury.Methods:Twenty-four SD rats (males, body weight 60 - 80 g) were randomly divided into T-2 toxin group (administrated T-2 toxin 100 ng·g -1·d -1 by gavage) and control group (administrated equal amounts of deionized water by gavage) using a random number table method, 12 rats in each group. After 4 weeks of intervention, the articular cartilage was collected for transcriptome sequencing. Deseq2 software [ P < 0.05 and |log 2(fold change)| > 1, fold change was the multiple of differential expression] was used to identify differentially expressed circRNA. Based on the competing endogenous RNAs (ceRNA) hypothesis, the miRanda software was used to predict the microRNA (miRNA, miR) binding sites of differentially expressed circRNA, and Cytoscape 3.10.0 software was used to plot the circRNA-miRNA interaction network. MiRWalk 3.0, MiRDB, and miRTarBase softwares were used to predict downstream target genes, and Cytoscape 3.10.0 software was used to map the circRNA-miRNA-mRNA interaction network. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the biological functions and enrichment pathways of target genes. Results:A total of 19 differentially expressed circRNAs were screened (including 10 upregulated and 9 downregulated). A total of 1 320 miRNAs binding sites and 16 target genes were predicted. Target gene enrichment analysis revealed significant enrichment of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathway ( P < 0.05). Tumour necrosis factor receptor-associated factor 6 (Traf6) and interleukin-1 receptor-associated kinase 1 (Irak1) were enriched in the MAPK and NF-κB signaling pathways, with corresponding miRNA and circRNA of miR-146a-5p and chr2: 94716330|94720889. Conclusion:Nineteen differentially expressed circRNAs in rat articular chondrocyte injury are successfully screened, and chr2: 94716330|94720889 may regulate the MAPK and NF-κB signaling pathways through the miR-146a-5p/Traf6/Irak1 axis, inducing articular chondrocyte injury.