Guided-mode resonance reflection filters are presented by adding a buffer layer in designing homogeneous thin-film reflection filters for studying the influence of buffer layer on reflection spectra of the guided-mode resonance filters. With the thickness increase of buffer layer, the reflection spectra of guided-mode resonance filters with one, two, three and four channels are calculated with the rigorous coupled-wave theory, two, three and four narrowband reflection peaks are found. When the buffer layer is chosen as 796.35 nm, the filling factor from 0.2 to 0.9, and the depth of grating between 100 nm and 200 nm, the resonant wavelength location and reflection ratio are nearly invariable, showing good characteristic of the filters.