Abstract: This paper reviews the studies on compressible mixing layerduring the past decade. These researches may beclassified into stability analysis, laboratory experiments and numericalsimulations, with a focus on the effectsof compressibility on other properties of mixing layer, including the growthrate, unstable modes, flow field structure, mean velocities and fluctuatevelocities, and the scalar mixing. The three aspects of researches complement eachother and give abundant information to understand the compressiblemixing layer. The researches cover an important part of the study onturbulent mechanism, and are essential for successful applicationsof mixing layer in technical areas.