Abstract: The experiments on 2:1 rectangular prisms with rounded corner ratios R/D of 0%, 5%, 10% and 15% are reported. The tests were performed in low-turbulence uniform flow to measure the surface pressure of four models for the Reynolds number ranging from 1.1 × 10⁵ to 6.8 ×10⁵. Aerodynamic force coefficients are obtained by pressures integration. The effects of the Reynolds number on aerodynamic force coefficients and their power spectrums are analyzed. The results are summarized as follows: As the rounded corner ratio increases, the drag coefficient of the model decreases and becomes more sensitive to the Reynolds number. The RMS values of drag and lift coefficients for the four models all have considerable Reynolds number effects, and the RMS values become more sensitive to the Reynolds number with the increase of rounded corner ratios. The power spectrums of drag and lift coefficients for rectangular prisms R/D=0% or 5% are not changed with the Reynolds number, but when R/D=10% or 15%, the power spectrums have considerable Reynolds number effects. In addition, the rounded corner has a significant influence on the Strouhal number of 2:1 rectangular prisms.