Ran numerical analysis about simplicity warm current model (simple turbulence model) to examine closely distributed laying stress on NOx of contaminant that happen in downtown that building is massed and result is as following. Downtown building is massed and transfer of vehicles can know that frequent area receives greatly effect of building. Pollution displays class kind phenomenon striking in the building, class kind done pollution that show high density being mixed with pollution that happen in vehicles being flowed in again side know can. Divide velocity vector of pollution and density change to ancient city and did numerical analysis. Because NOx is flowed in diversion of water neighborhood by continuous this kind in Godo 20m point, density showed density of $0.0907mg/m^3s$, and can know that Banryuhyeon that Pollution strikes in the building at ancient city 30m point is decreased and approaches with freedom flowing without cooperation (cavity) phenomenon remarkably. Because pollution strikes in the building at distance shaft 383m point, class kind do phenomenon that know appeared notedly Nopeungeonmulgwanat between building pollution density $0.067mg/m^3$ head of a families high appear.