In the recent years, heart rate variability (HRV) has been increasing recognized as a non-invasive monitoring technique to evaluate the function of autonomic nervous system. This article expounded the method of HRV analysis and introduced the relationship between HRV and the autonomic nervous system, while the current clinical methods to monitor the depth of anesthesia were compared. Meanwhile, this article explained the relationship between anesthetics and HRV, explored and prospected the application of HRV in monitoring the depth of clinical anesthesia.