The　one-index　site　classification　based　on　the　equivalent　shear　wave　velocity　of　rock　and　soil　layers　within　a　specified　depth　as　the　control　parameter,　and　the　two-index　site　classification　based　on　the　equivalent　shear　wave　velocity　of　soil　layers　within　a　specified　depth　and　the　thickness　of　overlying　soil　layers　as　the　control　parameters,　are　the　two　major　categories　of　site　classification　methods.　The　applicability　and　rationality　of　the　two　categories　of　methods　have　consistently　been　focal　points　of　attention　and　discussion　within　the　engineering　community.　The　primary　purpose　of　engineering　site　classification　is　to　judiciously　consider　the　site　effects　on　strong　motion　to　determine　the　seismic　design　ground　motion　parameters　for　construction　projects.　The　degree　of　consistency　in　the　spectral　characteristics　of　strong　motion　records　within　the　same　classified　site　stands　out　as　the　most　effective　criterion　for　elucidating　the　rationality　of　the　site　classification　methods.　Utilizing　strong　motion　records　from　the　Japanese　strong-motion　seismograph　network　KiK-net　and　related　site　borehole　data　of　the　observation　stations,　the　statistical　analysis　was　conducted　to　delve　into　the　distinctions　and　merits　of　the　existing　site　classification　methods.　Initially,　the　site　classification　of　the　observation　stations　was　carried　out　using　the　site　classification　methods　including　the　specified　in　seismic　design　codes　from　countries　such　as　China,　the　United　States,　and　Japan,　and　several　recently　proposed　ones,　and　then　the　collected　strong　motion　records　are　grouped　accordingly.　Subsequently,　statistical　analyses　of　acceleration　response　spectra,　including　the　peak　acceleration,　were　performed　for　ground　motion　acceleration　records　from　the　observation　stations　with　the　same　site　class　specially　for　different　site　classification　methods.　The　study　also　scrutinized　the　consistency　and　clustering　property　of　acceleration　response　spectra　for　strong　motion　records　from　the　observation　stations　with　the　same　site　class　across　various　site　classification　methods　through　the　statistical　residual　analysis.　The　research　findings　reveal　that,　among　the　site　classification　methods　studied,　the　site　classification　method　of　the　Chinese　seismic　design　code,　a　two-index　site　classification　method　based　on　the　equivalent　shear　wave　velocity　of　soil　layers　and　the　thickness　of　the　overlying　soil　layers　as　the　control　parameters,　is　deemed　as　the　optimal　method.　©　2025　Chinese　Society　of　Civil　Engineering.　All　rights　reserved.