Based　on　George　Gazetas＇　formulas,　the　dynamic　stiffness　and　damp　of　the　fundation　are　calculated.　The　static　and　dynamic　action　of　the　soil　to　the　foundation　is　simplified　as　a　spring-dashpot　system　in　the　structural　analysis.　A　three　dimensional　model　for　a　paramid　grid　truss　with　rigid　foundation,　independent　foundation　and　strip　footing　is　established　by　ANSYS　software.　Then　the　effect　of　the　soil-foundation-structure　interaction　on　the　static,　the　dynamic　characteristics　and　the　seismic　response　of　a　24m×30m　space　grid　are　studied　respectively.　The　research　shows　that　the　natural　frequency　will　be　lower　and　the　period　will　be　longer　after　the　consideration　of　soil-foundation-structure　interaction.　When　the　stiffness　of　the　foundation　meet　the　requirements　of　the　load　and　the　deformation　the　effect　of　the　soil-foundation-structure　interaction　on　the　static　behavior,　vibration　characteristics　and　seismis　response　of　the　space　grid　can　be　ignored,　at　the　same　time　the　design　and　the　calculation　method　based　on　the　solid　foundation　assumption　are　reliable.