This paper presents empirical-mathematical model of turbo-charging for the Diesel engine with sequential turbocharging. The model is based on application of the SW 680 engine characteristics obtained on the basis of average parameters of a cycle as well as fl ow characteristics of turbochargers, for the description of which the methods of multiple regression have been used. The conditions of the turbocharger co-operation with the traction engine have been taken into account by means of pulsation coeffi cients, which ensures suffi cient convergence of numerical calculations with the results of experimental testing.