Abstract: In order to study the time-space characteristics of vortexflow field in axial compressor, a time-critical CFD method was employed tonumerically simulate the flow field in a single rotor. After the mass flowanalysis at different axial positions in the rotor, it is found that thefluctuation value of inlet mass flow is 2% normalized by the maximum massflow. In addition, it is also found that the oscillation of vortex flowfield at suction side near the trailing edge was the main reason for theinlet mass flow fluctuation.