In this research, the chemical and structural attributes of two flavonoid compounds, Kaempferol and Apigenin, have been investigated employing DFT. These compounds are considered the most promising options for high-sensitivity gas sensors. Applying DFT computations, the adsorption behaviour of typical gas molecules over Kaempferol and Apigenin was studied. Apigenin (Kaempferol) could respond to physisorption of CO and CO2 molecules sensitively due to their considerable charge transfer (CT). Particularly, notable progress in transport performance is induced by absorption of both CO and CO2, which makes Apigenin (Kaempferol) an appropriate option to detect CO and CO2 molecules sensitively. In order to examine potential application of natural products in sensing toxic gases, we deeply believe that this work supplies guidance for research groups.