Aiming at the wind-tunnel experimental models with and without gas dispersion provided by the Architectural Institute of Japan（AIJ）,15 turbulence models are employed to simulate the outdoor wind environment.Then,by the comparison between the simulated results and the wind-tunnel experimental ones,the optimal turbulence model for the numerical simulation of outdoor wind environment around a building is determined.The results show that Suga's cubic high-Re k-ε model is the best due to its high accuracy of simulating both the air flow and the pollutant diffusion,but the CPU time of it is longer than that of the standard k-ε model.Thus,during the CFD numerical simulation of the outdoor wind environment of a building,Suga's cubic high-Re k-ε model can be used when the time is enough,and the standard k-ε model can be used when high accuracy is not required and when the calculation time is limited.