The dimensionless nonlinear dynamical equations of tilted support packaging system with vulnerable components were obtained under rectangular pulse excitation, and the numerical results of the shock response were studied using Runge-Kutta method. Three-dimensional shock response spectra was established with the ratio of the maximum shock response acceleration of the vulnerable components to the peak pulse acceleration, the pulse duration and the frequency ratio of system as three basic parameters. The effects of the angle of system, the peak pulse acceleration and mass ratio on the shock response spectra were discussed. The results showed that with the increase of the peak pulse acceleration, or the decrease of the angle, the maximum shock response acceleration of the vulnerable components increase rapidly, and the effect of low frequency ratio on response of system is particularly sensitive; increasing frequency ratio of the system can obviously decrease the maximum shock response acceleration of the vulnerable components, and the peak of the shock response of the vulnerable components decreases at low frequency ratio by increasing mass ratio. The purpose was to provide academic foundation for design of tilted support packaging system.