Unsteady three-dimensional thermal analysis model of the chamber wall is used to account for the thermal protection of GO₂/kerosene ground test engine and numerical calculation is performed on its water cooling channel wall. The numerical model treats the hot gas flow and coolant flow as one dimensional. The hot gas side heat transfer and the temperature profile in the wall are obtained by finite difference method. The history of the temperature profile is also predicted by the analysis. The effect of the coolant flow rate on the temperature profile is also discussed.