In this paper, the important characteristic parameter, namely the mass loss rate, was obtained by the
investigating on CF/ S-157PF composite under oxyacetylene flame test conditions. And using multiple linear regression, the mathematic model on the mass loss rate and the two major factors, namely the heat flux density and ablation time is as follows: M = 0. 043·q0. 128·t-0. 191 . It is verified that, the regression model is very applicable and the fore cast accuracy is much better. So the erosion properties of CF/ S-157PF composite can be evaluated with this rapid, effective and accurate method in the oxyacetylene flame test.