Abstract: To investigate the role of auxin-induced gene NtIAA13 in potassium uptake and utilization in tobacco, a gene designated NtIAA13b with a total length of 879 bp and encoding 292 amino acids was cloned using the cDNA of tobacco K326 as a template. The expression characteristics of NtIAA13b in different tissues under different abiotic stress conditions were systematically analyzed by qRT-PCR and subcellular localization, and the overexpression strain of NtIAA13b was obtained by transgenic technology to verify its physiological function. The results showed that the protein encoded by NtIAA13b had a relative molecular mass of 31.71 kD and a theoretical isoelectric point (pI) of 6.48. The promoter region of NtIAA13b contained auxin-responsive element TGA-element and gibberellin-responsive element P-box, as well as regulatory element ARE that was involved in anaerobic induction. The subcellular localization results showed that the protein was localized in the nucleus. The phylogenetic tree results showed that NtIAA13b and tomato SlIAA13 were closely related. The real-time PCR results showed that NtIAA13b had the highest expression level in roots, followed by stalks and leaves with the lowest expression levels. Under normal potassium supply conditions, overexpressed strains significantly increased leaf potassium content. The NtIAA13b gene is thus associated with tobacco response to hypokalemic stress and may be involved in the uptake and utilization of potassium in tobacco.