Abstract: This article proposed an optimization method for inter-station running time distribution of a train, as the line speed between two stations was limited. The inter-station line could be divided into several intervals based on the number and the values of the speed limits which influence the speed profile directly. The Energy-Time function of each interval could be calculated through function fitting. The article established an augmented objective function via Lagrange multiplier. The simulation was taken by Matlab, and the optimization results for inter-station running time distribution were obtained by the Quasi-Newton method. This method could be applied to lines with different speed limits if the Energy-Time function of every interval could be obtained. This method was tested based on the hardware environment of the CMC chip .