The effect of quenching and aging temperature on ordering process of AuCu alloy was investigated.Based on the experimental results obtained, we concluded that1. The ordering process of AuCu alloy can be divided into two stages: 1) formation of short-range order or nucleation with increase in resistivity, followed by 2) long-range ordering with decrease in resistivity.2. The ordering kinetics of AuCu alloy during low temperature aging is mainly limited by migration of the quenched-in vacancies. The rate of ordering process is proportional to the concentration and mobility of quenched-in vacancies.3. The formation energy and migration energy of vacancies in AuCu were estimated to be 0.95 eV and 0.81 eV respectively.4. During isothermal aging, the quenched-in vacancies in AuCu decayed according to the law of second-order reaction.