In previous researches (Baker, 2010; Cheli et al., 2010),it is confirmed that the aerodynamic loads acting onthe structure induced by wind can be expressed by thecorresponding non-dimensional coefficient, remainingthe same direction with the wind and only depending on the shape of the structure at a certain Reynoldsnumber. Therefore, the non-dimensional aerodynamiccoefficients, defined by Equation (3), are adopted todescribe the aerodynamic forces in the most investigations in crosswinds. However, the coefficients only show the ultimate effect in a condition of the train-inducedwind and cross wind and the individual contributionresulting from the moving train, incoming wind and themutual influence between them cannot be presented. Forthis reason, we can approximately make a basic assumption that the aerodynamic forces on the train are redefined as