Base flow is the main source of river in dry season.The stable and reliable method of base flow separation is of importance to base flow research. Based on the daily discharge data of Luoshan station from 1965 to 2012,the paper used five methods which include the base flow index method, fixed interval method, sliding interval method, local minimum method and digital filtering method to separate the base flow. The results show that there are little differences among five methods, but the base flow process varied significantly between the five methods in a year. The results of BFI method and local minimum method are more reasonable and have better identification in different years.The method is a suitable mean of base flow separation in the middle area of the Yangtze River.