It　is　of　great　interest　to　predict　dynamic　response　of　large　-size　structures　based　on　model　test　results,　which　is　a　crucial　criterion　for　structural　design　and　damage　assessment.　To　achieve　this　goal,　the　dimensionless　number　D　g　is　proposed　for　predicting　the　dynamic　plastic　response　of　beams　and　plates　subjected　to　impact　loading　based　on　dimensional　analysis.　The　suggested　dimensionless　number　has　clear　physical　significance　where　the　geometrical　features,　material　characteristics,　impact　location　and　impact　loading　are　incorporated,　and　these　physical　parameters　are　easily　available.　What　＇s　more,　the　empirical　models　are　developed　based　on　the　proposed　dimensionless　numbers　for　predicting　transverse　deflection　of　metal　components　subjected　to　impact　loading.　The　effectiveness　of　the　proposed　dimensionless　number　is　verified　with　multiple　groups　of　test　data.　It　is　found　that　the　proposed　empirical　model　can　be　used　to　accurately　predict　the　deformation　of　plates　and　beams　with　different　materials　subjected　to　impact　loading.　Compared　with　typical　prediction　models,　the　empirical　expressions　fitted　by　deflection　-thickness　ratio　and　dimensionless　number　D　g　are　linear　rather　than　complex　nonlinear　relationship,　where　the　suggested　dimensionless　number　D　g　has　excellent　correlation.　The　simple　empirical　equations　are　capable　of　predicting　impact　tests　with　a　range　of　different　impact　loading,　geometric　dimensions　and　material　properties.　Therefore,　the　suggested　empirical　models　can　help　scholars　validate　their　experimental　and　analytical　results,　and　engineers　avoid　any　unnecessary　repetition　of　experiments　during　the　design　process.