In　order　to　discuss　the　effect　of　field　difference　on　peak　acceleration　and　spectrum　values　of　seismic　response,　dynamic　numerical　analyses　of　the　free　field　around　shenzhen-laojie　subway　station　with　both　dynamic　characteristics　and　step-by-step　integration　methods　are　conducted　by　using　Lanczos　eigenvalue　extraction　technique　to　obtain　natural　frequencies　and　modes,　and　by　Newmark　implicit　method　to　solve　dynamic　equations　based　on　considering　geometric　and　material　nonlinearity.The　computational　results　show　that　the　distributions　of　frequency　spectrum　for　the　soft　layer　of　silty　soil　and　sandy　clay　display　typical　twin　peak　feature　and　the　spectrum　values　corresponding　to　high　frequency　content　decrease　apparently.Furthermore,　the　twin　peak　feature　of　frequency　spectrum　for　the　layer　of　coarse　sand　and　artificial　fill　is　not　clear,　and　the　spectrum　amplitudes　of　peak　platform　corresponding　to　dominant　frequency　content　increase　comparatively.Therefore,　both　seismic　frequency　spectrum　and　acceleration　spectrum　of　the　free　field　show　typical　seismic　characteristics　of　medium-soft　field.　©　2016,　Editorial　Department　of　Journal　of　SJZU.　All　right　reserved.