军团菌肺炎的临床表现无特异性，容易误诊。当患者出现呼吸困难、腹胀腹痛、神经系统症状等时是重要线索。低钠血症、谷丙转氨酶和谷草转氨酶异常升高是重要肺外表现。动态观察血清抗体滴度变化是诊断要点。本文误诊５例，死亡２例。提示：及早诊断、及时应用足量红霉素或红霉素加利福平是降低死亡率的关键。 Legionella pneumonia non-specific clinical manifestations, easy to misdiagnosis. When the patient has dyspnea, abdominal distension, neurological symptoms, etc. is an important clue. Hyponatremia, abnormal elevation of alanine aminotransferase and aspartate aminotransferase are important extrapulmonary manifestations. Dynamic observation of serum antibody titer changes is the diagnostic point. This article misdiagnosed 5 cases, 2 died. Tip: Early diagnosis and timely application of sufficient erythromycin erythromycin or erythromycin is the key to reducing mortality.