The method for quantitative estimation of 4,5-dimethoxy-N-phenylanthranilic acids was defined by the two-phase titration. Principle of the method consists in direct titration by alkali solution of two-phase system which is compounded of organic phase that encloses substances being analyzed, and of water phase that encloses indicator. The endpoint size of titration is defined according to decolorization of the water layer. The method is characterized by a high accuracy, simplicity, expressiveness. Relative error in the method does not exceed 0.5 %.