Abstract: The mat wall cooling is a new semi transpiration cooling scheme.A heat transfer model of the mat wall cooling is established and a numerical iteration method is employed to calculate its cooling parameters (i.e.thermal effectiveness and wall temperature ratio) in the porosity range from 0 0204 to 0 0625.It is shown that the cooling parameters are affected mainly by the porosity and coolant flow number,and the boundary conditions have insignificant effect.The calculated results are consistent with the existed experimental data.This fact indicates that the presented heat transfer model is principally adequate,but must be further improved for more accurate prediction.