Hexa-, tetra- and mono- fatty acid esters of myoinsitol were synthesized by various methods, e.g., by heating myoinositol or its 1, 2-isopropiridene derivatives with acid anhydrides of various fatty acids, or by ester exchanging reaction with methyl esters of fatty acids under coexistence of sodium methoxide as catalyst.Of the fatty acid esters of myolnosltol prepared, hexaacetate, hexapropionate and hexabutyrate showed similar growth promoting effect as free myoinositol upon young rats, whereas hexavalerate, tetrabutyrate, monooleate and monolinoleate showed no influence, and some of them showed rather inhibitory effect. These three esters that possess growth promoting effect in rats showed beneficial effect for the prevention of fatty liver in the Handler's experimental systems. The lipotropic action of myoinositol hexanicotinate was quite obscure.Some probabilities for the application of these fatty acid esters of myoinositol were briefly discussed in connection with their physicochemical properties.