Abstract: Train braking force is one of the important loads for the design of railway bridges. The maximum braking force of unit locomotive and carriage is theoretically analyzed and calculated through experiments and theoretical analyses on different braking coefficients and braking characteristics of freight trains. A program ZDL was developed. By conducting dynamic calculations on heavy haul freight trains with different lengths presently in operation in China, the maximum braking force ratio of 0.2 and the effective braking force ratio of 0.17 are obtained for bridge structures with different lengths. The simulated results agree well with that of the real bridge in emergency braking tests. The dynamic calculation method for full-range dynamic description when emergency braking is applied to heavy haul freight train is proposed. The results of the present study provide one basis for determining the braking forces on railway bridges.