This paper proposes a design of PID-level controllers in chemical plants based on IMC principles. Controller parameters of a common simple PID controller are given. This method is also applicable to integrating systems with time delay. Unlike most IMC-based design studies, this study also proposes a method for determination of the IMC filter time constant based on statistical analysis of about 200 level controllers in actual chemical plants. The proposed controller design method is applied to a typical integrating system to demonstrate its effectiveness. The design method is finally applied to level controllers in actual plants. The result shows significant improvement both in the deviation of the control variables and the fluctuation of the manipulation variables.