目的　观察脑干枪弹伤的形态学变化。　方法　切取 2例头部枪弹伤死亡后 2 5min的脑干 ,对中脑与脑桥被盖部和延脑第四脑室深部组织做电镜观察。　结果　中脑枪弹伤波及整个脑干及小脑 ;脑干枪弹伤超微结构见烧灼伤和冲击、压力伤两种 ,其特点是广泛性神经轴索损伤重 ,神经元损伤轻 ;轴索烧灼伤呈现轴索水肿 ,髓鞘、轴浆及其线粒体浓缩、变形 ;冲击、压力伤呈现轴突扭曲、变形、融合、挤压、缺损、破裂致轴浆内容物外流或缺失、错位、神经微丝与微管偏向轴索一侧等。　结论　网状结构严重广泛性神经轴索损伤与对机体的致命性有着重要关系。 Objective To observe morphological changes of brain stem bullet wounds. Methods Two cases of brain gunshot wounds were killed after the head gunshot wounds were killed. Electron microscopy was performed on the deep part of the midbrain and the pons of the pons and the fourth ventricle of the medulla oblongata. Results Cerebral-brain-gunshot wounds affected the entire brain stem and cerebellum. The ultrastructure of brain-gun bullet wounds was found to be burn burns and shock and pressure injuries, which were characterized by extensive axonal injury and mild neuronal damage. Axonal burns Axonal edema, myelin, axoplasm and mitochondria were concentrated and deformed. Axial distortions, deformation, fusion, extrusion, defect, and rupture were caused by shock and pressure injury. And microtubules axial side and so on. Conclusion The severe and extensive axonal injury of the reticular structure is closely related to the lethality of the body.