Abstract: The effect of a new casing treatment on the axial flow compressors rotating stall precursor wave was comprised in a three-dimensional rotating stall stability model presented in this paper.It is verified to be accurate enough in prediction of the inception of rotating stall compared with several experimental results.With the application of the equivalent surface source method,the interaction between the precursor wave and the casing treatment could be calculated.This means that there is a theoretical way to design the casing treatment.Some numerical experiments were conducted to evaluate the roles played by the structural parameters of the casing treatment.The result shows that adequate combinations of these parameters could extend the stall margin of a high-speed compressor.