The highest flavone content of buckwheat is in its flowers,the mean value is as high as 7.4%.After flowering,the value will decrease gradually.The flavone content of buckwheat leaves is lower,its mean value is 5.3%,its highest peak appears at the stage of flowering,then decreasing slowly.The flavone content of buckwheat stems is the lowest, its mean value is 1.0%,no obvious change in the whole growth of the plant.Among the buckwheat grains,tatary buckwheat grains contain the highest flavone content,the mean value is 2.02%.The mean flavone content value of common buckwheat is only 0.23%.Radiative treatment-s can increase the flavone content of buckwheat.The formation of flavonid compounds of buckwheat is mainly controlled by PAL activity.