The heterogeneous catalytic conversion of dimethyl ether (DME) to 1,3-butadiene and butylenes in the presence of a ZnO/gamma-Al(2)O(3)catalyst in a wide range of temperatures, feed space velocities, and reactant concentrations has been studied. It has been found that temperature regions of 380-420 and 440-480 degrees C, which are conventionally designated as low-temperature and high-temperature regions, differ in the laws governing the occurrence of the process associated with the specificity of coking of the catalyst surface and a redistribution of the surface concentration of Bronsted and Lewis acid sites. A hypothesis of a change of the catalytic process mechanism upon the transition of the reaction into the high-temperature region has been put forward and confirmed by the occurrence of a hysteresis detected in this temperature range. The effect of hydrogen peroxide on the hysteresis parameters and the steady state stability during DME conversion has been shown.