Abstract: The program SIMPLEC has been adopted to calculate the viscous flows at all Mach numbers inside a plane cascad and nozzle.In order to tread both incompressible and compressible flows,pressure is chosen as a primary dependent variable in preference to density.The effect of the pressure on the density is implicitly included in the pressure correction equation.Further,the covariant velocity components are chosen as the dependent variables in the momentum equations,which makes the pressure velocity coupling relatively easy to handle.Comparison of the calculated results with the experimental data show that the present method exibits much better stability and covergence behavior,and is applicable to a variety of the incompressible and compressible flows,ranging from subsonic to supersonic.