Abstract: Appropriate ecological flow is the guarantee of river health. Analysis and calculation of the appropriate ecological flow of rivers has important practical significance. Nanting River, as the mother river of Lincang City, may be dehydration due to rapid development of diversion power station in the upper reaches and that relevant regulations content(Any organizations and individuals who draw water from the Nanting River Basin shall simultaneously design, construct, and use ecological flow discharge facilities to ensure that the discharge flow is not less than 10% of the average flow for many years) in“Lincang City Nanting River Protection and Management Regulations” cannot truly reflect the seasonal changes in ecological flow. Using the 55-year daily average flow datum of Nanting River Dawen Station and 60 years of Gulaohe Station, Using Tessman method and monthly flow variation method were adopted to calculate the suitable ecological flow in the river channel of each control section in Nanting River. The results showed that the ecological water demand of Tessman method was greater than that of monthly flow variation method. The change trend of ecological flow by Tessman method and monthly flow change method were consistent with that of natural runoff. The satisfaction rate of ecological flow calculated by monthly flow variation method was greater than that calculated by Tessman method. Based on the factors of ecological water demand, seasonal variation of ecological flow and satisfaction rate, the monthly flow variation method was used to calculate the suitable ecological flow of rivers with obvious seasonal variation such as Nanting River, and the results seemed more realistic. According to the analysis and calculation results of this paper, it was suggested to revise the ecological flow of different river sections in the Nanting River Basin and to issue it for implementation.