Abstract Experiment of natural diffusion of liquid membrane is the reaction in liquid membrane, in which contrast phenomena of natural and continuous change from reactants to resultants through intermediates can be observed easily and clearly. This article studied the changes of reaction of KMnO4 and Na2SO3 with the acidity and alkalinity of solutions, reactions of FeCl3 and KSCN, K4[Fe(CN)6] and NaOH, the formation process of the complex of Co2+ and SCN- and the phenomena of the diffusion process of litmus solution in acid and alkali solution in self-made drip pans. The experiment is green, simple and less dosage, and its phenomena can be demonstrated by projector or recorded as teaching materials.