Abstract: In order to expand the ways to utilize discarded tobacco stalks, a simple and environmentally friendly method of steam explosion for the production of xylooligosaccharide (XOS) was investigated. The reaction pressure and pressure holding time of the steam explosion treatment were investigated for the depolymerization of hemicellulose components in tobacco stalks to XOS. Tobacco stalks before and after steam explosion were characterized by SEM and ATR-IR. The results showed that: 1) Most of the hemicellulose component of tobacco stalks was successfully depolymerized to XOS. As much as 6.85 g of XOS per 100 g tobacco stalk was obtained under 1.8 MPa reaction pressure with 300 s reaction time. However, higher pressure or longer holding time could degrade XOS and decreased the yield. 2) The fiber structure was destroyed and most of the hemicellulose was depolymerized, but the cellulose and lignin components in the tobacco stalks were well preserved during the process. The developed method shows a good potential for the utilization of tobacco stalks to produce fine chemicals.