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The interaction between shock wave and turbulence has been studied in supersonic turbulent mix layer wind tunnel. The interaction between oblique shock wave and turbulent boundary layer and the influence of large vortex in mix layer on oblique shock wave have been observed by NPLS technique. From NPLS image, not only complex flow structure is observed but also time-dependent supersonic flow visualization is realized. The mechanism of interaction between shock wave and turbulence is discussed based on high quality NPLS image.shock wave, turbulent boundary layer, turbulent mix layerThe interaction between shock wave and turbulence is one of the most complex phenomena in supersonic flow. A study on it can help to understand the mechanism of shock wave and turbulence flow more deeply. This phenomenon often presents in supersonic turbulent mix layer flow. While pressure is equivalent between two layers, the primary characteristics are the generating and developing of coherent structure. If not equal, interaction between shock wave and turbulent mix layer and boundary layer will appear, which will lead to a very complex flow field. Generally speaking, the interaction between shock wave and turbulence can be classified as: interaction between shock wave and homogeneous turbulence, interaction between shock wave and turbulent jet, and interaction between shock wave and turbulent boundary layer, etc. [1] . Interactions between shock wave and turbulent boundary layer and mix layer are studied in this paper.Rose and Johson studied the interaction between shock wave and turbulent boundary layer [2] . An oblique shock wave was generated at the opposite wall to that of the boundary layer by a sharp edge in their experiment, but no high resolution turbulence image was acquired. Andreopoulos and Muck, Erengil and Dolling, and Beresh also studied it with different methods with the influence of pressure fluctuation and movement of large scale structure taken into account [3][4][5] , but more detailed analysis could not be realized because of the limitation of resolution. Settles, Hayakawa and Samimy have studied the interaction between oblique shock wave and turbulent mix layer. In their experiments, the turbulent mix layer is generated from a concave, and oblique shock wave is generated by a sharp edge. But they only dealt with the influence of Mach number on turbulent intensity due to limitations of testing system [6][7][8] . There are also some computational results on the interaction between shock wave and turbulence. Horstman and Visbal attempted to predict the flow structure using Reynolds-averaged Navier-Stokes methods, but the result showed that the predicted turbulent intensity was not accuracy. More recently, LES and DNS have been invoked to study the interaction between shock wave and turbulence with the development of computer technology. Ducros has studied the interaction between normal shock wave and homogeneous turbulence with LES [9] . Adams studied the interaction between shock

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