OBJECTIVE: To investigate the therapeutic effect of the herbal medication Xiao Pi-II on the symptoms and gastric motility of patients with functional dysepsia (FD). METHODS: A total of 180 FD patients were divided randomly and equally into Xiao Pi-II and mosapride groups. The two groups were treated with Xiao Pi-II (100 mL, t.d.s., ante cibum) and mosapride (5 mg, t. d.s., ante cibum) for 2 weeks. Before treatment and 3 days after all medication was stopped, patients responded to a questionnaire evaluating gastrointestinal symptoms and were assessed with abdominal three dimensional ultrasonography (3D-US) for gastric motility. RESULTS: Gastrointestinal symptoms (especially bloating, post-prandial fullness and eructation) were improved significantly in FD patients treated with Xiao Pi-II (P0.05). The effective rates in the Xiao Pi-II and mosapride group were 86.7% and 60.0%, respectively (P0.05) of GLER in the mosapride group. CONCLUSION: Compared with mosapride, Xiao Pi-II improved symptoms and GLER significantly in FD patients with delayed gastric emptying.