Abstract: As the key component of the riparian ecosystem,the riparian buffer zone plays an important role in the ecohyrological process,which has been taken a key measures in riparian ecosystem management by many countries,especially as the Best Management Practices(BMPs) in non-point pollution control for agricultural watershed in some developed countries.The eco-hyrological functions of riparian buffer zone focus on aspects such as bank erosion control,sediment and nutrients retention,water quality protection,water temperature regulation,wildlife habitat,stream biodiversity and ecosystem integrity maintainence as well as the riparian landscape quality improvement.This paper reviews the advances in the research on the eco-hyrological functions of riparian buffer zone,and summaries the width of riparian buffer for various ecological functions requirement,which will be determined by many factors such as protection goals,soil,topography,vegetation and drainage of study site.