先天性左房瘤是一种罕见的心脏畸形。至今国外文献仅报告４０余例，国内仅７例。我们报告１例５岁女孩术前无症状，胸片发现左心缘扩大，超声心动图明确诊断。在体外循环下行瘤体切除，治愈出院。结合文献对本病临床特点、诊断、治疗及预后进行讨论。 Congenital left atrial tumor is a rare heart malformation. So far only foreign documents have reported more than 40 cases, only 7 cases in China. We reported a 5-year-old girl who was asymptomatic preoperatively. The chest radiograph revealed a widening of the left pericardium and a definitive diagnosis using echocardiography. The tumor was removed under the cardiopulmonary bypass and cured. Combined with the literature, the clinical features, diagnosis, treatment and prognosis of the disease were discussed.