Abstract: The depression cone of pumping wells reflects the hydrogeological conditions of aquifer, such as hydraulic parameters and elastic storage of confined aquifer. The geometrical shape and volume of depression cone has important application value. According to the Theis equation, during the late period of pumping tests on non-leaky confined aquifer, the relationship between drawdown and distance is a straight line in s-lgrfigure, and that between drawdown and time shows a straight line in s-lgtfigure. These characteristics are often used to calculate hydrogeological parameters and influence radius. Applying the integration method, the volume of depression cone of pumping well in non-leaky confined aquifer is derived by regarding the drawdown and distance as integration variables. A contrast to the exact solution shows that the depression cone within the influence radius calculated by means of the straight line of s-lgris proportional to the entire drawdown cone. The difference between the above two depression cones is pointed out.