The　soil　response　to　large　earthquakes　is　strongly　nonlinear,　which　has　a　significant　influence　on　the　performance　of　buried　infrastructure　as　well　as　input　motion　to　superstructures.　This　paper　reports　on　uniform　and　nonuniform　multi-point　shaking　table　tests　to　elucidate　the　effect　of　soil　non-linearity　on　free-field　soil　response.　Emphasis　was　placed　on　investigating　the　effect　of　the　non-uniform　seismic　excitation　in　different　directions　on　the　soil　response.　The　tests　were　conducted　on　scaled　sand　deposits　enclosed　in　a　suspension　continuum　soil　box　using　three　shaking　tables　that　can　induce　uniform　and　non-uniform　seismic　excitations.　Quantitative　analyses　were　performed　to　study　the　ground　motion　response　characteristics　and　variation　of　free-field　soil　characteristics　underground　motions　with　different　intensity,　frequency　content　and　directions.　The　analyses　evaluated　the　soil　dynamic　characteristics　and　their　variation　with　strain　level,　as　well　as　soil　acceleration　and　settlement　responses.　The　results　demonstrated　that　the　soil　nonlinear　behavior　is　influenced　by　the　ground　motion　intensity,　direction　(longitudinal　or　transverse)　and　uniformity.　Non-uniform　ground　motion　may　lead　to　more　pronounced　changes　of　soil　structure,　which　would　decrease　the　soil　profile　natural　frequency　and　increase　its　damping　ratio.　The　variation　of　soil　shear　modulus　with　strain　also　reflected　the　soil　plastic　response.　The　longitudinal　excitation　had　a　more　pronounced　effect　on　the　soil　vertical　settlement　compared　with　the　transverse　excitation.　However,　non-uniform　excitation　had　a　minor　effect　on　the　soil　vertical　settlement.