Abstract: In order to develop a new approach for preparing flavors by Maillard reaction, molar concentrations of soluble sugars and free amino acids in water extracts of sweet potato, pumpkin and potato and pHs of the extracts were quantified. Three natural flavors were produced via the Maillard reaction of these water extracts. The aroma components in roasted sweet potato, pumpkin and potato were compared with those in corresponding natural flavors respectively. The potentials of the three natural flavors for improving the smoking quality of cigarette were verified by laboratory pyrolysis analysis and human sensory evaluation. The results showed that:1) Realistic and coordinated roasted sweet potato flavors (GS), roasted pumpkin flavors (NG) and roasted potato flavors (TD) could be prepared by using water extracts of the natural plants. 2) The main aroma components and volatile pyrolysis products in GS and NG were furans, furanones, pyranones and cyclopentenones compounds, and roasted sweet aroma was the main aroma characteristic of GS and NG. Adding GS and NG onto cut tobacco could strengthen the roasted sweet aroma note of cigarette smoke. 3)The main aroma components and volatile pyrolysis products in TD were pyrazines, pyrroles and pyridines compounds, and baked aroma was the main aroma characteristic of TD. Adding TD provided an outstanding baked aroma in cigarette smoke.