Abstract: After the implementation of the river（lake）chief system,the shoreline boundary and protection scope of Yunnan Province have not been delimited,which brings many difficulties to the control of lake shoreline space. Taking Qilu Lake as an example,the characteristics of periodicity and equilibrium of lake water level change are analyzed by wavelet function and the Gini coefficient,and the ecological water level,water boundary and outer boundary are determined by the method of water level guarantee rate,flood regulation and development.（1）The water level of Qilu Lake has oscillation periods of 10,15 and 25 years,with 25 years as the first main period,showing an insignificant upward trend. There are two abrupt changes in 1969 and 2009,with the most prominent one in 2009. The characteristics of water level change revealed by the Gini coefficient and precipitation fluctuation index are consistent with the results of wavelet analysis.（2） The minimum ecological water level ranges from 1 793.72 to 1 794.90 m,reaching the lowest in May and June while reaching the highest in December. The suitable ecological water level varies between 1 794.35 and 1 795.39 m,and the optimal ecological water level varies between1 795.22 and 1 796.21 m.（3） The boundary of the water is 1 793.92 m when lake water ecological restoration,basin water resources allocation planning and water supply security are considered. The optimal ecological water level of lake water ecological restoration and the factors of promoting flood control are taken into account,the outer boundary of the lake bank is 1 796.62 m. The results indicate that the operating water level stipulated by the Lake Protection Regulations can meet the requirements of shoreline demarcation and control.（4） Based on a spatial superposition analysis of the GF-3 satellite images,the shoreline space is designated as a protected area. This paper analyzes problems in shoreline management from the perspectives of responsibility transmission,supported means and social participation,and formulates the basic rules and requirements of shoreline management and control.