TheASYMMETRIC LEAVES2/LATERAL ORGAN BOUNDARIES(AS2/LOB) gene family plays a pivotal role in plant growth, induction of phytohormones, and the abiotic stress response. However, theAS2gene family inBrassica rapahas yet to be investigated. In this study, we identified 62AS2genes in theB. rapagenome, which were classified into six subfamilies and distributed across 10 chromosomes. Sequence analysis ofBrAS2promotors showed that there are several typicalcis-elements involved in abiotic stress tolerance and stress-related hormone response. Tissue-specific expression analysis showed thatBrAS2-47exhibited ubiquitous expression in all tissues, indicating it may be involved in many biological processes. Gene expression analysis showed that the expressions ofBrAS2-47andBrAS2-10were significantly downregulated under cold stress, heat stress, drought stress, and salt stress, whileBrAS2-58expression was significantly upregulated under heat stress. RT-qPCR also confirmed that the expression ofBrAS2-47andBrAS2-10was significantly downregulated under cold stress, drought stress, and salt stress, and in additionBrAS2-56andBrAS2-4also changed significantly under the three stresses. In addition, protein–protein interaction (PPI) network analysis revealed that theArabidopsis thalianagenesAT5G67420(homologous gene ofBrAS2-47andBrAS2-10) andAT3G49940(homologous gene ofBrAS2-58) can interact with NIN-like protein 7 (NLP7), which has been previously reported to play a role in resistance to adverse environments. In summary, our findings suggest that among theBrAS2gene family,BrAS2-47andBrAS2-10have the most potential for the regulation of abiotic stress tolerance. These results will facilitate future functional investigations ofBrAS2genes inB. rapa.