Abstract: Taking into consideration physical constraints of the plant, dynamie disturbance rejection control for scalar regulating system is discussed in this paper. A new controller, the transient compensator is proposed. It can strenthen dynamic disturbance resistibility of the system. And a design procedure based on the inverse problem of LQ optimal contal for a strong disturbance rejection controller (which shows small dynamic errors under a kind of disturbances and the output requlation property) is discussed. An example of a D. C. speed control system indicates that with this controller, the impact drop can be reduced effectively, and at the same time, the output regulation and sufficient stability margines can be guaranteed. Resuslts of system, physical experiement are also satisfactory.