One child was hospitalized because of repeated cough and sputum. The biopsy diagnosis in local hospital was cystic lymphangioma in retropharyngeal space. We carried out transoral incision and drainage by catheter under general anesthesia. Put into the surgical cavity a suction drainage tube, and injected 5 mg dexamethasone and 8mg Bleomycin. He had nasogastric liquid diet after operation. We removed the suction drainage tube two weeks later. No recurrence was found following up over two years.