3-D steady, unsteady numerical simulation of the effect to the subsonic axial compressor of three different type of circumferential total-pressure distortion: five distortion per revolution (5×24°), two distortion per revolution (2 ×60°) and one distortion per revolution (1×120°) .Detail analyses of the flow field of the rotor came to some preliminary conclusion: With the same distorted angle, one distortion per revolution extents imply a longer durations of increased loading and has much loss of stability margin; At the border of the distorted sector the flow vectors point inside the distorted sector. The loading of the rotor blades is decreased when the blades enter the distorted area and increased when the blades leave it. The inlet total-pressure distortion led to total-temperature distortion at the outlet.