A successive triple introduction of organophosphorus complexon DTPP (sodium-dicalcium salt of diethylene-triaminopentamethylphosphonic acid) in a dose of 500 mg/kg to albino male rats did not produce any marked effect on the composition of the peripheral blood. Some shortening of the initial period in blood coagulation process was noted. DTPP produced a moderate stimulation of the iron-containing enzymes (catalase, peroxidase, cytochroxidase) which led to an increased oxygen consumption. The blood serum and urine potassium, sodium and calcium content did not undergo any significant changes, while the magnesium concentration in the blood serum dropped by 37 pc and in the urine rose by as much as twice as compared to controls. This bears evidence to an elevated discharge of magnesium from the organism following the action of the DTPP complexon.