Time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra of polystyrene (PS)1 and poly (2,3, 4, 5, 6-pentafluorostyrene) (5FPS)2 films supported on silicon wafers were obtained at temperatures ranging from room temperature to 120 ℃.Principal component analysis (PCA) of the ToF-SIMS spectra of these two polymers revealed a transition temperature (Tr) at which the surface structure of PS and 5FPS was rearranged.