Compressible turbulent channel flows at two Mach numbers ( M = 018 and 113 ) are simulated by the numerical integration of the Navier-Stokes equations with a high- order compact finite difference scheme1 The comparative studies of incompressible and compressible flows indicate that the effect of compressibility on the scaling exponents is small in the region near y+ = 20 and in the center while it is significant in the viscous sublayer ( y+ = 51 5) and the log- law region ( y+ U 120) . Further studies on the variation of the relative scaling exponent show that the channel can be divided into four distinct zones according to their scaling behavior: viscous sublayer and lower edge of buffer layer ( Ñ ) ; the outer part of the buffer layer and lower part of log region ( Ò ) ; the major part of the log region and lower edge of the center region ( Ó ) ; and finally the other part of the center region ( Ô ) . The variation of the scaling exponents with the compressibility is the most remarkable in the zone Ñ and Ó . Finally, it is found that the most intermittent region exactly coincides with the location of the maximum Reynolds shear stress.