The ternary Al-Ce-Ni metallic glass-forming system in its Al-rich(〉60at．％)corner is investigated by experiments,thermodynamic modeling and First-Principle calculation．A consistent thermodynamic data set for the Al-Ce-Ni system is obtained by the optimization of the experimental data．The calculated isothermal sections,vertical sections and invariant reactions agree well with the experimental results．Using the results from thermodynamic assessment,the relationship between the glass forming ability(GFA)and phase diagram of the AI-Ce-Ni system is investigated．It was revealed that the alloys with good GFA in the AI-Ce-Ni system are in off-eutectic，indicating no deep eutecties in the AI-Ce-Ni system．It was found that the heats ofmixing of the alloys with good GFA are from-15 to-49 kJ/mol of atom．The alloy with euteetie composition has poor GFA due to the larger heats ofmixing．The results from melt-spinning experimental and the calculation of driving force of crystalline phases in supercooled liquid state indicated that the alloys with minimum driving force have good glass forming ability．It is thus concluded that the negative heats of mixing and minimum driving forces are the criterions for selecting the composition for formation ofthe Al-Ce-Ni metallic glass．