Abstract: To promote value-added transformation and utilization of tobacco resources, a hot water extraction method was used to extract polysaccharides from low-quality tobacco leaves. A novel glucoarabinogalactan, named WTLP2b, was isolated and purified by ion exchange chromatography and gel column chromatography. The structure of the WTLP2b sample was characterized using various analytical techniques, including ion chromatography, gel filtration chromatography, gas chromatography- mass spectrometry and nuclear magnetic resonance spectroscopy. The results showed that: 1) The WTLP2b obtained consisted of galactose (55%), arabinose (33%) and glucose (12%), with a molecular weight of 62.0 kDa. Methylation derivation and NMR analysis revealed that WTLP2b's main chain was composed of →6)-β-D-Galp-(1→, while the side chains consisted of β-D-Galp-(1→4)-β-D-Galp-(1→, α-L-Araf-(1→4)-β-D-Glcp-(1→, and α-L-Araf-(1→5)-α-L-Araf-(1→, connected to the main chain via O-3 bond of →6)-β-D-Galp-(1→. 2) The WTLP2b sample mainly showed a sheet-like structure with aggregated morphology. 3) The thermal stability of the WTLP2b sample was relatively good. The results of this study show that tobacco leaves can serve as a natural source of glucoarabinogalactan.