Numerical simulations of hypersonic flow around a 2-D cylinder and a 3-D complete reentry vehicle have been carried out by solving Euler/Navier-Stokes equations which incorporate the equation of state for an equilibrium gas. The governing equations are solved by an implicit finite volume TVD (Total Variation Diminishing) upwind scheme using a two-equation turbulence model for a viscous flow. Curve-fits for the thermodynamic and transport properties of an equilibrium air are adopted in order to estimate real gas effects. Convective fluxes are calculated by the Roe's approximate Riemann solver generalized for an equilibrium gas. The results of hypersonic flow analysis using this code suggest us that the real gas effects, such as chemical reaction, are not negligible to predict the hypersonic flow characterisics acculately.