Abstract: AP2/ERF (APETALA2/ethylene responsive factor) is one of families of transcription factors unique to plants, which plays an important role in controlling plant growth and development, participating in secondary metabolism and resisting abiotic stress. Based on the reported AP2/ERF genes in Arabidopsis thaliana, 142 AP2/ERF genes were identified in the newly published sesame (Sesamum indicum L.) reference sequences by bioinformatics. The physicochemical properties, phylogeny, domains, conserved motifs, chromosome localization, species collinearity, expression specificity in different tissues and gene expression response to stress were analyzed. According to the analysis of physicochemical properties, the AP2/ERF gene family of sesame encodes 121-697 amino acids, the relative molecular weight of the protein is 13428.04-76020.09 KD, and the theoretical isoelectric point is between 4.50 and 10.24. According to the analysis of domain and phylogenetic analysis, the AP2/ERF protein in sesame can be divided into four subfamilies: AP2 contains 26 members, ERF contains 116 members, soloist contains 2 members and Rav contains 3 members. 136 members are unevenly distributed on 16 chromosomes, and are clustered in homologous groups of chromosomes 1-4 and 6-12. According to the collinearity analysis, there are 32 and 49 AP2/ERF genes on Sesame chromosome, which are collinear with barley and maize respectively. In the evolution process, the conservation of AP2/ERF gene with maize is higher than that with barley, and the variability with barley is higher than that with maize. The LOC105157874 gene in subgroup VII was up-regulated in both sesame varieties, which may be involved in the regulation of sesame response to flooding stress and needs further experimental verification.This study provides a scientific basis for further study on the biological function of AP2/ERF transcription factor family and the improvement of sesame stress resistance.