Abstract: Using microwave expansion treatment tobacco stem, before and after the treatment tobacco stem were made cut stems according to the conventional process, 8 class 77 kinds of the aroma components of two kinds of cut stems were determined respectively and analyzed comparatively, and the smoking quality of two kinds of cut stems were evaluated. The results showed that: Compared to cut stems made of microwave treatment tobacco stem and by conventional process, alcohols and esters of the aroma components relative content had no significant difference. Phenolic and olefin hydrocarbon had significant difference, respectively was -10.98% and 10.33%. Aldehydes, ketones, acids and heterocyclic existed significantly difference, respectively was 27.54%, 12.99%, 39.15% and 30.83%; The smoking quality was improved obviously.