This paper discusses the distinction between internetworks and single network in the congestion control. It has shown the reason why all of single network s congestion controls are not suitable to internetworks. A new congestion control scheme for internetworks is presented which uses the acknowledgments of the timeouts and the feedback signal from the gateway as the indications of packet loss and congestion. Using a black-box model of the internetworks, the author derives several approximate calculating formulas and proves the schemes special characters by computer simulation. It is shown that the presented method is better than R. Jains method(1986).