Rhodiola quadrifida (Rq) roots and rhizomes are traditional natural drugs used in Asia as adaptogens and antidepressants. The aim of this work was to study the in vivo effect of aqueous and 50% hydro-alcoholic extracts of Rq rhizomes on the metabolic activity of blood granulocytes in mice. Mice were fed for 7 days Rq extracts in daily doses 50, 100, 200 or 400 µg. The metabolic activity of blood phagocyting cells was determined based on the measurement of their chemiluminescent activity in scintillation counter, after stimulation by zymosan. Both extracts stimulated granulocytes activity in 400 µg doses, in lower dose (200 µg) only hydro-alcoholic extract was effective.