In　this　study,　four　sets　of　steel　beams　of　three　strength　classes　with　similar　geometries　were　built　for　episodic　but　extremely　hazardous　impact　loads　to　investigate　the　scaling　effects　on　their　dynamic　responses　at　different　impact　energies,　mainly　analyzing　the　effects　of　structural　scaling　and　impact　energies　on　the　damage　modes　of　the　beams,　the　mid-span　displacements,　the　impact　forces,　and　the　support　reaction　forces.　The　results　of　the　numerical　study　show　that　when　the　impact　energy　is　low,　the　impact　response　of　the　steel　beam　conforms　to　the　classical　similarity　law.　This　is　demonstrated　by　the　fact　that　the　normalized　displacement,　impact　force,　peak　support　reaction　force,　and　member　energy　absorption　are　almost　the　same,　do　not　vary　with　size,　and　are　not　affected　by　steel　strength.　At　higher　impact　energies,　the　various　dynamic　responses　deviate　from　the　classical　similarity　law　by　up　to　45　%　and　are　less　affected　by　steel　strength.　The　scaling　effect　occurs　because,　at　high　energy　levels,　a　steel　beam　may　enter　a　plastic　state　or　even　yield.　The　area　(or　volume)　that　yields　and　the　extent　of　yielding　do　not　change　consistently　with　variations　in　size.　In　addition,　the　combination　of　static　loading　methods　yields　that　the　impact　energy　required　for　a　steel　beam　to　exhibit　the　scaling　effect　is　approximately　three　times　the　energy　needed　for　the　beam　to　enter　the　yielding　stage.　In　this　paper,　empirical　quantitative　formulas　(i.e.,　similarity　laws)　for　predicting　the　variation　of　steel　beam　displacements,　impact　forces,　support　reactions,　and　member　energy　absorption　with　size　are　given　based　on　numerical　simulations,　and　some　of　the　formulas　given　in　the　paper　are　verified　in　conjunction　with　previous　studies.