Abstract: Sensitivity analysis for coupled vehicle-track systems with uncertain parameters subjected to track irregularity is studied. The vehicle is modeled as a multi-rigid-body system and the track is regarded as an infinite periodic structure. The equations of motion are established in mixed physics and symplectic dual coordinate systems in the Hamiltonian system and the sensitivity equations with respect to the uncertain parameters are derived by using analytical method. The combined pseudo-excitation method and symplectic method is then used to derive the random response sensitivities for coupled vehicle-track systems. Numerical examples show that the proposed method has both highly accuracy and efficiency due to the application of pseudo-excitation method. The work is a good reference for the design and optimization of vehicle kinetic parameters.