The local modes (or optical branches) of the PdHx samples for x = 0.17 and 0.67 have been measured respectively with the Beryllium Filter Detector Spectrometer. It was observed that the position of the peak for the PdH0.67 is about 5 meV lower than that of the PdH0.17. The relation between the softening of local modes and the supercodue-tivity has been discussed qualitatively.