In this paper, classical control theory and Smith's principle are applied in designing a class of effective andsimple congestion control schemes for high-speed computer communication networks. Mathematical analyses and sim-ulations verify the efficiency of the congestion control schemes. The proposed congestion control laws guarantee fullutilization of network links and stability of network queues so that the network has no data loss in a general networktopology and traffic scenario. The approach has some advantage over the usual Smith's principle based congestioncontrol scheme; it can be applied to those networks that may have smaller bottleneck capacity. Theoretical analysesand simulation results show good performance of networks if implemented by the congestion controllers, which aredesigned on the basis of the improved Smith principle.