In　this　paper,　we　study　the　nonlinear　transient　responses　of　an　auxetic　(negative　Poisson＇s　ratio)　honeycomb　sandwich　plate　under　impact　dynamic　loads.　The　partial　differential　equations　of　the　honeycomb　sandwich　plate　based　on　Reddy＇s　higher　shear　deformation　theory　and　Hamilton＇s　principle　are　obtained.　The　nonlinear　ordinary　differential　equations　are　then　derived　by　Galerkin　truncation　method.　The　dynamic　responses　of　the　honeycomb　sandwich　plate　subjected　to　different　loads,　such　as　step　loading,　air-blast　loading,　sinusoidal　loading,　triangular　loading　and　incremental　loading,　respectively,　have　been　investigated.　The　contributions　of　total　thickness,　core　thickness　ratio,　Poisson＇s　ratio,　cell　inclination　angle　and　blast　types　to　transient　responses　of　the　plate　are　discussed　in　detail　by　numerical　simulations.　The　effect　of　geometrical　parameters　on　the　dynamics　of　the　plate　and　the　effect　of　different　blast　loads　on　the　plate　are　obtained.　It　is　found　that　the　honeycomb　sandwich　plate　with　negative　Poisson＇s　ratio　would　be　a　better　choice　compared　with　the　positive　one　for　some　structures　under　dynamic　loads.