To evaluate GC-rhEPO, human erythropoietin produced by recombinant DNA technique, its general pharmacological properties were investigated in experimental animals administering intravenously and in vitro test system. GC-rhEPO at doses of 70,700 and 7,000 IU/kg body weight had no influence on general behavior, spontaneous motor activity, thiopental-inducted sleeping time, writhing syndrome induced by acetic acid, strychnine-induced convulsions, charchoal meal propulsion in mice, and body temperature, gastric juice secretion, urine and electrolyte excretion in rats. In anesthetized rabbits, GC-rhEPO (70, 700 and 7,000 lU/kg, i.v.) did not alter respiratory rate, blood pressure, heat rate. In in vitro experiments, GC-rhEPO did not affect the contractions of the isolated ileum of guinea pigs and the muscle twitchs of isolated neuromuscular junction of the rats. In addition, GC-rhEPO did not affect the blood coagulation time and ADP-induced platelet aggregation in plasma of rabbits. Taken together, these results indicate that GC-rhEPO does not induce any adverse effects in the experimental animals.