Abstract: The partially-parabolic governing equations of the three-dimensional compressible turbulent flow in an S-shaped duct with rectangular section are derived from the generalized form of the Navier-Stokes equations in mass-everaged variables assuming the flow to be predominant along the longtitudinal direction. The k-e turbulence model modified in the study can deal with the compressible flow situation in the S-duct. The momentum, energy and turbulence model equations are solved by finite-difference method. The analytical results of the static pressure distributions along the walls, total pressure recovery and three-dimensional velocity at outlet of the duct are in fairly good agreement with the experimental data. This fact implies that the numerical approach can be developed to solve the three dimensional compressible turbulent flow in a complicated S-ducts,