The crystallization peaks were observed to shift towards higher temperature with respect to the increasing heating rate in all the glasses which is because of delay in attaining thermal equilibrium. Ray [17] has reported that Tg is related to the density of covalent cross linking, number and strength of co-ordinate links formed between oxygen atoms and the cations and the oxygen density of network. Higher values of these factors correspond to higher Tg. In case of BaY glass, Y3+ might be acting as the network former where it may have higher number of covalent cross linking. The non-bridging oxygen due to modification of glass network by Ba2+ might be bonded by Y3+ cations which lead to the higher Tg of this particular glass as compared to the BaLa and BaAl glasses. Interestingly, the cation field strength might not be playing very important role to govern the glass transition temperature since the field strength of Al3+ has high value as compared to the Y3+and La3+cations. Thermal data obtained from DTA measurement of these glasses was used to calculate the thermal stability and activation energy for crystallization.