The rotor blade unsteady aerodynamic force in a single-stage low speed compressor with inlet guide vane(IGV) was simulated numerically in this paper.By analyzing the unsteady blade force located on leading edge and trailing edge of the rotor tip and hub

the adding effect of the upstream wakes and downstream potential effect was illustrated.The upstream wakes affect the whole blade chord range while the downstream potential effect influences only part of the trailing edge.By shifting the clocking position of IGV and stator blade

the amplitude of whole rotor pulsant pressure force can be reduced by 19.4%

while on leading edge of the rotor tip

it can only be reduced by 9.4%.