An integrated structure/control system design method is applied for the control system of the D-3 VTR tape path system. For the purpose of obtaining an integrated structure/control anlytical model with high accuracy, an analytical model of the VTR tape path mechanism is constructed first so as to represent the dynamic characteristics of a mechanism well. The integrated structure/control model is made by combining the VTR mechanism model with a control system model. This integrated model enables us not only to obtain sensitivity information for design improvement but to optimize mechanical and control system simultaneously. Control system design optimization is performed using this integrated analytical model to reduce tape tension fluctuation under high acceleration and deceleration operation. The advantage of this integrated analytical model and new control system is shown by the test using the prototype system.