Raman and infrared spectra measurement of (50-x)AlF3-xYF3-50MeF3 (Me= Ca+Ba+Mg+Sr, x=0, 10, 15, 20, 30) glasses have been conducted. A1F3 and YF3 skeletons in glass structure are discussed based on the vibrational spectra. It ia shown that the structure unit in a glass without YF3 is composed of both [AIF6]3-octahedrons and [AlF4] ~ tetrahedrons. In the case where a part of A1F8 is replaced by YF3 in glass compositions, however, the YF3 will be present in the form of 8-coordination in glass structure.