In this contribution, the optical Fuchs-Kliewer (FK) surface phonon and hydrogen adsorption of 6H-SiC surfaces were investigated with high-resolution electron-energy-loss spectroscopy (HREELS). The different HREEL spectra of the FK surface phonons were obtained from clean (0001) Si- and (0001) C-terminated surfaces. It was noticed that the full width at half maximum of elastic peaks for the reconstructed surfaces was smaller than that of unreconstructed surfaces for both (0001) Si- and (0001) C-terminated 6H-SiC. Under decomposing ammonia by hot filament at 1700 degreesC, only the adsorption of hydrogen atoms on the surfaces for both Si- and C-terminated 6H-SiC was detected in the experiment.