Abstract: In order to get delicious food and give instruction to food process, the essence of food flavour was explored according to a great deal of food flavour experience. The influences of chemical composition of food on flavour were discussed, six flavour laws such as theory of main flavour,theory of suitable concentration, theory of equilibrium stimulation, theory of multi-level flavour,theory of flavour music and theory of stimulation passivation were summed up and explained by a lot of examples. The influences of physical properties of food such as texture, temperature, specific heat on flavour were also discussed.