When a plane moving shock wave encounters an inclined wall, it is reflected by the wall. In these reflection problems of a shock wave, regular and Mach reflections have been observed in previous shock tube experiments. However, in regard to the transition between these reflections, there are many problems which have not yet been resolved. The problem considered in this report is that of nonlinear interaction between a shock wave and an inclined rigid wall in pseudo-steady and unsteady flows. Experimental investigations of transition criterion were performed using carbon-dioxide as a working gas, and the domains and boundaries of these reflections are discussed in this paper. 4 refs.