Abstract: The family of bHLH transcription factor plays an important regulatory role in plant response to stress. Cloning and validation of bHLH related genes in tobacco can provide a theoretical basis for tobacco resistance breeding. In this study, we cloned an NtbHLH112 gene from the common tobacco variety K326. To further investigate the function of NtbHLH112, the bioinformatic analysis, subcellular localization and transactivation activity of NtbHLH112 were carried out. We also analyzed the expression pattern of NtbHLH112 under different stress treatments by using qRT-PCR. The results showed that NtbHLH112 had a highly conserved and typical bHLH domain and was localized in nucleus. Moreover, NtbHLH112 had transactivation activity. Phylogenetic analysis suggested that NtbHLH112 was homologous with SlbHLH112 and CabHLH112. The qRT-PCR results demonstrated that NtbHLH112 was highly expressed in leaves and was up-regulated by the treatments of salt stress, high-temperature, cold-temperature and ABA. Therefore, NtbHLH112 as a typical bHLHtranscription factor, may play a significant role in abiotic stress of tobacco.