Far-infrared reflectivity spectra have been measured for the first time on ZnSe-ZnTe strained-layer superlattioes grown by molecular beam epitaxy. The spectra at 300 K display the ZnSe and ZnTe transverse optical phonon modes. The reflectivity spectrum can be explained by the long wavelength superlattioe dielectric theory and the reflection theory of multiple absorbing layers. Fitting the experimental data with the computer calculated curve, the transverse optical phonon frequences, mode damping consbants, mode oscillator strengths and high frequency dielectric constrant have been determinded.