CJ-50001 is a recombinant granulocyte-colony stimulating factor (rG-CSF) synthesized by recombi-nant DNA technology using E. coli as an expression system. The general pharmacological properties of CJ-50001 were evaluated in mice, rats, dogs and isolated guinea pig ileum. The doses are 100, 300 and 1, 0007g/kg, i.v. for mice and rats, 1, 10 and 100$mu$g/kg, 1.v. for dogs and 1 and 10$mu$g/ml for isolated guinea pig ileum. Intravenous administration of CJ-50001 at this dose range did not affect general behavior, central nervous system, smooth muscles, gastrointestinal system, cardiovascular and respiratory system and water and electro-lytes excretion. In summary, CJ-50001 had no harmful pharmacological erect in these studies even up to the 200-fold expected clinical dose, 2507g/man.