1. The kinetics of the formation of guanosine 5′-triphosphate, 5′-diphosphate, and 5′-monophosphate in the reaction of the morpholide of guanosine 5′-monophosphate with bis-(tributylammonium) pyrophosphate in pyridine at 27° has been recorded. 2. In the reaction of the morpholide of guanosine 5′-monophosphate with bis-(tributylammonium) pyrophosphate, four successive reactions take place: those of the formation of an intermediate compound, of GTP, of GDP, and of GMP. The maximum formation of GTP (67%) occurs after 2 hours and of GDP (67%) after 24 hours. 3. A preparative method for obtaining pure tetrasodium guanosine 5′-triphosphate from the morpholide of guanosine 5′-monophosphate with its isolation from the mixture by chromatography on DEAE-cellulose in a linear gradient of triethylammonium bicarbonate has been developed. The yield calculated on the basis of the morpholide, is 61–65%.