Abstract: In order to study the effects of aging on the usability of flue-cured tobacco stems from China, 14 stem samples of upper and middle tobacco leaves were collected from 7 representative tobacco planting areas and cut stems were aged for up to 6 months. The physical characteristics (including color, luster, filling value), sensory quality, tar and CO releases in mainstream smoke and the cigarette's hazard toxicant index (H) were analyzed during 5 aging periods. The results showed that:1) Aging influenced the color, luster, filling value, sensory quality of the cut stems, and tar and CO released in mainstream smoke was also greatly affected. 2) With the proceeding of aging, the color of dark and light cut stems was improved. The luster of cut stems was promoted. The filling value of cut stems decreased sharply first and then increased. The sensory quality of cut stems improved slightly first and then deteriorated sharply. The tar released greatly declined and CO release greatly raised. 3) Aging gradually narrowed the differences of color and luster among the cut stems from different areas, and reduced the differences in filling values and tar levels from different areas.