The dynamic behaviour of sandwich plates with auxetic core subjected to air blast loading is investigated numerically. The plates are considered to be made of carbon/epoxy face sheets and auxetic cores in the shape of "antitetrachiral" and "missing rib". The air blast loading is described by Friedlander decay function. The sandwich plate subjected to air blast loading is modeled by using the finite element method. An explicit analysis is performed. The displacement time history and the displacement and stress distributions on the plate and auxetic core are obtained at the time of peak displacement. The results obtained for sandwich plates with antitetrachiral and missing rib auxetic cores are compared and discussed.