【Abstract】Background Near-infrared spectroscopy (NIRS)is a new non-invasive method of monitoring cerebral oxygen saturation,it can provide useful information about brain oxygenation situation.Because of its sensitive,real-time,continuous and simple operation advantages ,it widely used in clinical in recent years.Objective This paper focuses on recent advances in the application of NIRS to do a review and provide a reference for clinical work. Content The passage contains the theory of NIRS,clinical application and influence factors.Tend NIRS monitoring for cerebral oxygen saturation can detect brain’s oxygen supply and demand balance and can found cerebral blood flow changes early.It’s useful for anesthesiologist change his management to prevent cerebral ischemia and hypoxia.It has great clinical application foreground.