目的探讨脑溢安颗粒（简称脑溢安）治疗脑出血的作用机制。方法立体定位内囊注射胶原酶（Ⅶ型）诱导大鼠脑出血模型， Griess法检测血肿周围大脑皮质内一氧化氮（ nitric oxide, NO）含量，光镜观察脑组织病理改变。结果模型组大鼠大脑皮质 NO含量显著高于手术对照组（ P< 0.01）。脑溢安组大鼠大脑皮质 NO含量较模型组相应时间点明显降低（ P< 0.01）。结论脑溢安可能通过减少脑内 NO产生，对脑出血损伤发挥保护作用。 Objective To investigate the mechanism of Nao Yi An Granule (Nao Yi An) in the treatment of cerebral hemorrhage. Methods The intracerebral injection of collagenase (Ⅶ) was stereotacticly induced into intracerebral hemorrhage model. The content of nitric oxide (NO) in the cerebral cortex around the hematoma was detected by Griess method. The pathological changes of brain tissue were observed with light microscope. Results The content of NO in cerebral cortex in model group was significantly higher than that in control group (P <0.01). Nao Yian rat cerebral cortex NO content than the model group corresponding time point was significantly lower (P <0.01). Conclusion Nao Yi An may play a protective role in cerebral hemorrhage injury by reducing NO production in the brain.