Objective To evaluate the efficacy and safety of maintenance therapy with reduced dose of rh TPO in the patients with primary immune thrombocytopenia(ITP)who attained stable platelet(PLT)counts after daily administration of rh TPO.Methods Treatment was started with a daily administration of rh TPO(300 U/kg)for 2 consecutive weeks.Patients who attained stable PLT≥50×10~9/ Objective To evaluate the efficacy and safety of maintenance therapy with reduced dose of rh TPO in the patients with primary immune thrombocytopenia (ITP) who attained stable platelet (PLT) counts after daily administration of rh TPO. Methods Treatment was started with a daily administration of rh TPO (300 U / kg) for 2 consecutive weeks. Patients who attained stable PLT ≥ 50 × 10 ~ 9 /