New oxyfluoride glasses were prepared in the form MoO3-BaF2-xRF where RF is alkali fluoride (LiF, NaF and mixed NaF-LiF) with x = 5, 10, 15, 20, 25, 30 and 35 mol%. The densities of the studied glasses were measured and the molar volumes were calculated. Thermal properties like glass transition temperature T-g, the onset of crystallization temperature T-x, crystallization temperature T-c and melting temperature T-m were determined by using the differential scanning calorimetry (DSC) technique and from which the glass stability S and the glass forming tendency K-g were calculated. Values of thermal expansion coefficient alpha and specific heat C-p of the present glasses were also measured. All the above properties are correlated with composition alkali fluoride RF content and structure of the glass.