The excessive use of water resources,not only affects the sustainable development of the river basin or region but also destroys the water ecological environment to a certain extent.Therefore,it is necessary to conduct scientific accounting and regulation research on water resources,which not only guarantees the sustainable use of water resources but also maintains the healthy life of rivers,by studying the ecological base flow of rivers and ensure the maintenance of a certain flow in the river.The Luan River surrounds Beijing and Tianjin from the northwest to the southeast.It is an important and irreplaceable water conservation area and ecological support area for Beijing and Tianjin.It is also responsible for the important task of supplying water to Tianjin and Tangshan.As an important water resource link,the study of the ecological base flow of the Luan River is essential to ensure the healthy life of the Luan River. The current ecological base flow research of Luan River lacks a variety of hydrological methods to comprehensively analyzing the ecological base flow.Therefore,7 hydrological methods are used to calculate and analyze the ecological base flow of the typical section of Luan River. [JP+3]Monthly flow data of the Guojiatun hydrological station and Sandaohezi hydrological station from 1980 to 2016,the QP method,the tenant method,the frequency curve method,the typical hydrological frequency year method,the NGPRP(norther great plains resources program) method,and the driest monthly average flow in the past 10 years are used comprehensively.According to the characteristics of the runoff of different months in the Luan River during the flood period and the low water period,the upper and lower limits of the ecological base flow value of the relevant sections in each month are finely divided.The outcomes show that the ecological [JP]base flow value of the Sandaohezi section is from 1.10 m3/s to 6.06 m3/s,and the ecological base flow value of the Guojiatun section is from 0.78 m3/s to 5.66 m3/s.The monthly flow rate of the two sections for 37 years was tested with the above-determined ecological base flow value.The results showed that the ecological base flow in most months of the two sections for 37 years can be guaranteed.In two sections in December,January,and February the ecological base flow guarantee rate of the section is relatively low.[JP] The maximum ecological base flow at the Sandaohezi section of Luan River is 6.06 m3/s,the minimum ecological base flow is 1.10 m3/s,the maximum ecological base flow at the Guojiatun section is 5.66 m3/s,and the minimum ecological base flow is 0.78 m3/s,respectively.The QP method,frequency curve method,Tenant method (10%),the driest month average flow method in the past 10 years,focus on the ecological base flow during the dry period,and the calculated ecological base flow value is smaller.The NGPRP method focuses on the study of ecological base flow during normal water periods,and the calculated ecological base flow value is larger,which is suitable for rivers with sufficient water resources in the south to determine the use of ecological base flow.The ecological base flow guarantee rate of the two sections in December,January,and February are low.Measures such as reasonable division of water rights,scientific dispatching projects,the establishment of a monitoring system should be adopted to ensure the ecological base flow.