The kinetic viscosities of superheated liquids on the Gd-based bulk glass-forming alloys are measured by an oscillating viscometer in a high vacuum atmosphere. According to the viscosity data,the parameters of superheated liquid fragility,M,are calculated. Based on the values of M in Gd-and Pr-based (cited from the lit-erature) glass-forming alloys,we find that there is a linear correlation between M and the absolute value of mixing enthalpy,|ΔHmix|,in an alloy system with the same base element,and the larger M,the smaller |ΔHmix|. The alloy with larger M exhibits the larger height of energy barriers separating the minima on the potential energy landscape.
