Abstract: A new k-ω-γ transition/turbulence model is established toconsider the instability modes associated with the compressibility. Theparticular features of the new model are: (1) the fluctuating kinetic energyk includes the non-turbulent, as well as turbulent components modelled withthe stability analysis; (2) a function for the source term in γequation isdeveloped to trigger the transition onset; (3) it is strictly based on localvariables by introducing a new length scale normal to wall and compatiblewith the modern CFD methods. The present model was numerically proved to beapplied into the analyses of natural transition and bypass transition with awide range of Mach number.