This paper deals with the study of the anti-inflammatory and membranotropic activity of dimephosphone, mephoprane and new chemical synthesis products belonging to different series of substitut-ed phosphonic acid derivatives - monophosphonates. The effect of monophosphonates on the intensity of carrageenin inflammation in mice and rats was studied. The relationship of chemical structure and membrane-protective activity was analyzed on the models of osmotic and free-radical hemolysis. It was established that the organophosphorousc compounds - derivatives of alkylphosphonic acids - show anti-inflammatory and membrane-tropic activity. The anti-inflammatory and membrane-tropic activity of functionally substituted monophosphonates depends on the length of the hydrocarbon radicals in the ester fragments of the molecule: the greater length and the presence of the methyl radicals and a carbonyl (carboxyl) group in the alkyl frag-ment of the molecule provide greater activity. The greatest activity has a 2-carbobutoxypropyl-phosphonic acid dibutyl ether - ephorane (IIId)
