Abstract: In order to deeply analyze the performance of Yunnan tobacco leaf extracts, tobacco leaves from Yuxi, Kunming and Qujing were extracted with ethyl acetate to obtain Yunnan tobacco extracts. The Yunnan tobacco extracts were separated into four-class light fractions and a final heavy fraction by four-step molecular distillation. The major chemical components in the five fractions were analyzed with GC-MS, the thermal behaviors of the five fractions were compared with TG-DTG, and the flavoring effects of the five fractions were compared with sensory evaluation methods. The results showed that Yunnan tobacco extracts could be separated into fractions with different functions. On chemical components, the first and second light fractions contained a high level of volatile components, the third light fraction had more semi-volatile components, while the forth light fraction and the final heavy fraction were rich in nonvolatile components. On thermal behavior, the weight loss temperatures for the four light fractions were 220, 250, 310 and 400℃, respectively. For sensory quality, the first and second fractions could improve the quality and quantity of cigarette aroma, while the other fractions influenced the taste and smoke indexes.