Objective　To observe the curative effect and sid e effect of the gastrokinetic agent mosapride citrate by RCT. Methods　 42 cases of functional dyspepsia (FD) were divided into two groups rando mly, the group of mosapride(21 cases):orally administrated mosapride, 5mg, t.i.d for 4 weeks, and the control (21 cases):orally administrated domperidone, 5mg, t.i.d for 4 weeks. Symptoms and side effects were recorded before and at d 14, d 28 after administration of the medicines according to GCP and double blind pri ciple. Gastric empting test was also carried out in randomly selected patients. Results　Mosapride and domperidone were significantly effective on alleviating symptoms of the patient with FD. In mosapride treated group the half emptying time was shortened and the 120 min remain rate was reduced. No sid e effect was found. Conclusion　These results suggest that mosa pride 5 mg t.i.d. is effective and safe on alleviating symptoms of patients with FD and improving the ga stric empting time.