Abstract: In order to elucidate the general quality indexes of natural flavors, 5 indexes closely related to sensory quality of natural flavors, including the contents (mass fractions) of water, organic solvents, volatile components, sugars and organic acids, were selected to establish their mass fraction determination methods respectively. Two hundreds and fifty-eight natural tobacco flavor samples were investigated, and relevant data were analyzed using the t-Distributed Stochastic Neighbor Embedding algorithm. The results showed that: 1) The mass fraction distribution of 5 chemical indexes in different kinds of natural flavors showed obvious characteristics, which can effectively reflect quality differences among related products. 2) The results of verification using three common commercially available natural flavors as examples showed that the total mass fractions of the five selected chemical indexes in the natural flavor samples were all above 70%, constituting the main chemical components of common commercially available natural flavors. The five chemical indexes, i.e. mass fractions of water, organic solvents, volatile components, sugars and organic acids, could serve as universal chemical indexes for evaluating the quality and establishing standards for natural tobacco flavors.