According　to　the　site　classifications　and　their　uncertain　and　stochastic　characteristics,　the　site　classification　method　based　on　qualitative　reasoning　of　2-D　&　multi-rules　cloud　model　was　constructed　and　the　uncertain　division　of　the　site　classification　was　realized.　Then,　the　generator　on　2-D　&　multi-rules　for　uncertainty　reasoning　was　designed　to　identify　site　classifications　and　site　characteristic　period,　so　the　continuity　of　the　site　classification　and　site　characteristic　period　were　actualized.　This　method　got　rid　of　the　illogical　discontinuity　and　appreciable　distinction　displayed　on　the　code　chart　between　the　site　edges,　basically　realized　the　unification　of　the　site　classification　between　code　of　seismic　design　of　buildings　and　special　structures.　Finally,　74　examples　were　analyzed　by　the　method.　It　was　shown　that　the　sites　were　classified　with　the　correct　rate　of　97.3%,　and　the　method　proposed　in　the　paper　proved　to　be　effective　and　feasible.