The　wave　input　model　(WIM)　cannot　express　the　non-uniform　characteristics　of　ground　motions　completely.　By　analyzing　the　spatial　evolution　of　seismic　waves　from　the　source　to　the　site,　the　incident　site　waves　are　proved　to　be　complex　waves.　A　strategy　for　improving　the　WIM　by　expanding　incident　waves　to　complex　waves　is　proposed.　The　new　model　is　named　the　non-uniform　wave　input　model　(NUWIM).　The　NUWIM　is　accomplished　by　the　deterministic　incident　site　waves　and　the　visco-elastic　boundary　and　is　verified　by　the　analytical　ground　motion.　The　result　shows　that　the　advantages　of　WIM　in　simulating　the　wave　propagation　effect　and　the　radiation　damping　effect　are　inherited　in　the　NUWIM,　which　can　effectively　achieve　the　input　of　complex　incident　site　waves.　Compared　with　the　WIM,　the　non-uniform　characteristics　of　ground　motions,　such　as　time　delays,　peak　variations,　and　time　history　shape　differences,　can　be　synthetically　simulated　by　the　NUWIM.　©　2024　Tsinghua　University.　All　rights　reserved.