Long-term effective use of clophelin was observed only in 1/3 of pregnant suffering of hypertensive disease. The efficacy of treatment with this drug is determined not so much by its hypotensive action as by its influence oil the state of the central hemodynamics. Clophelin may often reduce the minute cardiac volume and thus, deteriorate the uterine-placental blood flow and that is why its use be carried out under meticulous control of the central circulation. The authors designed a mathematical model for the prognosis of the efficiency of long-term clophelin treatment in pregnant women with hypertensive disease.