A software modality FSP (foundational software platform) is becoming more and more important in recent years for it has a significant influence of applications on it. However, it is inconvenient to measure FSP because there isnpsilat an appropriate method to identify the quality model of it. This consequently leads to the result that itpsilas unable to guarantee the quality of its applications. A new method DSR (Delphi stepwise regression) is introduced in this paper. It combines the ideas of Delphi method with stepwise regression analysis and so avoids the shortcomings of both of them. On one hand, it uses the idea of Delphi to identify potential factors which may affect the result and therefore optimize the input of stepwise regression; on the other hand, it uses the idea of stepwise regression to reduce the influence of objective factors to the result. The quality model of FSP using this method is given in the end.