Abstract: Jinan spring catchment has four spring groups:Baotu Springs,Heihu Springs,Zhenzhu Springs and Wulongtan Springs. Since the 1950s,the average flow of springs has been decreasing from 36.6×10~4 m~3/d to the current level of 8×10~4 to 12×10~4 m~3/d. Springs base flow is a component of the relatively stable runoff,which is an important source of downstream river,and it is an important guarantee to maintain the ecosystem health of river course and lake. The paper calculates the base flow of Baotu Springs group in different frequency years,determines the stable base flow index,and calculates the spring base flow in different level years,and the ecological water demand of downstream river is calculated by using the inflection point method. This paper analyzes the relationship between the ecological base flow of spring water and river water demand,reveals the influence of karst springs on the health of rivers,lakes and other ecosystems in Jinan,and provides an important technical support for the protection of springs water in Jinan.