Aerodynamic characteristics of square prism with rounded corner ratio R/D=0.4 are studied through rigid model pressure-measured wind tunnel tests in uniform wind filed. The wind direction ranges from 0°to 45°. The Reynolds number Re ranges from 0.8×105 to 3.8×105. The results show that the mean drag coefficient，mean lift coefficient， fluctuating valuse of lift coefficient and Strouhal number under different wind directions are basically affected by Reynolds number. Compared with other wind directions，Reynolds number has a greater influence on mean drag coefficient and mean lift coefficient under wind direction of 0°~17.5°，a greater influence on fluctuating value of lift coefficient under wind direction of 7.5°~45°，and a greater influence on Strouhal number under wind direction of 0°~12.5°.