Fluoride glasses based on ZrF4-BaF2-CsF doped with BaCl2 up to 10 mol% have been prepared. Crystallization behaviour of these glasses has been investigated by means of DTA and XRD. Addition of 5 mol% BaCl2 into the fluoride glass of the ZrF4-BaF2-CsF system enhances the glass forming ability and the thermal stability against crystallization, but the glass forming ability is decreased for glass containing 10 mol% of BaCl2. The results have been discussed from the view point of thermodynamics and the dynamics of glass formation.