Abstract: Three cases of acute agranulocytosis in the elderly caused by drugs were reported. We primarily treated these patients with GM-CSF ie our hospital and all were cured. The rise in peripheral blood WBC count and neutrophils plus band forms were seen within 3-14 days after the infusion of GM-CSF was started. The elevation in WBC count was dose dependent, at doses of GM-CSF 120μg/per square meter of body surface per day or higher the WBC count continued to increase until the end of the course. They recovered completely within 6-15 days. The authors recommended that 120-180μg/per square meter of body surface per day, or 3.5-5μg/per kilogram body weight per day may be the suitable doses of GM-CSF, GM-GSF was administered by continuous Ⅳ infusion through 4-6 hours disulved in 5％ glucose solution 500ml for 5-7 days, The side effects of GM-CSF were also discussed.