Abstract: Aiming at the problem of dynamical failure for a single layer latticed shell under dynamic loads, the types and characters of dynamical failure were studied. A new quantity index based on the maximum displacement and plastic accumulative dissipated energy was constructed by discussing the dissipated energy mechanism. Taking a K8,6 single layer latticed shell of a 40m span as an example, two failure mechanism, the dynamic instability and dynamic strength failure, and corresponding characters were researched. Moreover, the failure form with different initial conditions was analyzed in detail. The computational results show that the dynamical instability failure occurs abruptly and that the dynamical strength failure occurs gradually, and that the form of dynamical failure can be judged by using the changing law of the dynamical failure index.