The Reynolds-averaged Navier-Stokes equations are solved numerically for supersonic flow over a blunt fin mounted on a flat plate with Roe third-order flux differencesplitting scheme. Turbulence eddy-viscousity is computed by Baldwin-Lomax model,Johnson-King model and Launder-Sharma k - model. The pressure distributions arein good agreement with experimental results. Some features, such as two reversed-flowsupersonic zones and secondary vortex structure are predicted well. The comparativestudy suggestes: (1) The Wilcox compressibility correction is more potent than sarkarcorrection for the case. (2) Johnson-King model provides a better overall simulation.(3) The performances of three different kinds of turbulence models are essentially thesame, but the computation efforts increase one by one.