Jerk　is　the　time　rate　of　acceleration,　reflecting　the　variation　of　structural　forces.　The　study　on　jerk　and　its　response　spectra　can　enhance　the　recognitions　on　the　non-stationary　of　ground　motion.　The　mechanical　meaning　and　research　value　of　jerk　is　described.　The　calculating　methods　for　jerk　are　discussed　and　their　performance　and　disadvantages　are　compared.　The　solution　method　of　elastic　and　inelastic　jerk　response　spectra　under　ground　motion　is　established.　The　characteristics　of　jerk　response　spectra　are　studied　according　to　the　influencing　factors,　such　as　a　site　condition,　an　amplification　factor,　a　ductility　factor　and　a　reduction　factor.　The　concept　of　an　impact　reduction　factor　is　presented.　The　analysis　results　show　that　jerk　influences　the　building　structures　with　short　or　middle　periods　more　obviously,　and　the　impact　responses　can　be　reduced　significantly　when　the　structural　ductility　is　enhanced.　The　impact　reduction　factor　increases　with　the　incensement　of　a　structural　natural　period　and　the　influence　of　jerk　on　long-period　structure　can　be　ignored.