目的　探讨 B超诊断纵隔肿瘤的特征和鉴别诊断的价值。方法　对 2 2例纵隔肿瘤患者通过观察肿块的形态、内部结构和物理性质 ,同时对照手术、病理结果确定 B超诊断。结果　超声提示的诊断与手术、病理结果相符。结论　 B超对纵隔肿瘤性质的诊断有一定的帮助 ,对确定手术方式和选择纵隔穿刺点有一定的价值 Objective To investigate the characteristics and differential diagnosis of mediastinal tumors diagnosed by ultrasound. Methods Twenty-two patients with mediastinal tumor were diagnosed by B-mode ultrasonography by observing the morphology, internal structure and physical properties of the tumor and the control operation and pathological results. Results of ultrasonic diagnosis and surgery, pathological findings. Conclusions B-ultrasound can help to diagnose the nature of mediastinal tumor. It has some value in determining the surgical method and selecting the puncture site of mediastinum