The recession process of C/C nozzle of liquid propellant rocket engine is studied. The analytical model consists of both solid-phase and gas-phase conservation equations. The gas-phase turbulent reactive flow of boundary layer is analyzed with the Favre-averaged equations to account for variable density effects. The unsteady heat conduction equation is used to obtain the temperature distribution of the nozzle wall with the numerical computation. The effects of mixture ratio, film cooling, chamber pressure and the density of the nozzle material on the recession rate are discussed.