Based　on　the　strong　earthquake　acceleration　records　in　different　fault　distances　from　the　Chi-Chi　earthquake　in　Taiwan　(1999)　and　Northridge　Earthquake　(1994)　in　the　United　States,　the　statistical　analysis　and　parameter　fitting　are　performed.　It　is　obvious　that　the　occurrence　of　frequency　of　the　speed　pulses　appearing　in　ground　motion　records　decreases　with　increasing　fault　distances.　When　the　fault　distance　is　more　than　40　km,　the　occurrence　of　frequency　of　the　velocity　impulse　is　very　small.　Beyond　this　range,　the　effects　of　speed　pulses　can　be　neglected.　The　attenuation　law　of　pulse　peak　with　increasing　fault　distances　is　also　observed.　Result　show　that　either　for　Chi-Chi　earthquake　or　Northridge　earthquake,　the　general　attenuation　of　pulse　peak　(vg　and　vp)　is　very　fast.