Crash energy absorption by a vehicle body structure is a very important role in the vehicle design stage. One of the most effective ways to increase the crash energy absorption capability of the body is to raise the dynamic buckling strength of beam or thin shell structures subjected to the axial compression. Static buckling problems have been thoroughly studied and the relationship between physical or material properties and buckling strength is well established. However, the properties of dynamic buckling have not been studied well. For example, in dynamic collapse phenomenon the buckling load increases and a higher order buckling mode appears as the impact velocity increases. It means that the structure which absorbs enough amount of energy in static collapse does not always behave in the same manner in case of dynamic collapse. Such complex characteristics make it difficult to simulate dynamic buckling accurately and to find out the optimum structure efficiently. In this study, the dynamic buckling phenomenon of a simple column including material plasticity was examined in detail using a finite element analysis. The analysis revealed the relationship between impact velocity and a higher order mode of buckling. The result indicates that it is necessary to introduce a numerical imperfection, representing a higher order buckling mode under a given velocity, in order to simulate dynamic buckling accurately. It has been known that crash problems does not accept a sensitivity analysis because of their nonlinear history curves. A new approach to apply a sensitivity analysis to dynamic buckling problems including material plasticity is presented, which treats a higher order buckling eigenvalues. This method can indicate the most effective location to modify in order to increase the buckling strength of vehicle body structures. The analysis results also show that the impact induced wave propagation has a large effect on dynamic buckling modes of the structure, which can hardly be observed in physical experiments.