Abstract: In the construction of the first 1 000 kV double-circuit transmission line from the south of Anhui province to the East parts of China, there have been two different schemes on the selection of neutral metal oxide arrester beside the neutral grounding reactor at the neutral point of the line shunt reactors. In scheme 1, the single column arrester with the rated voltage of 192 kV is selected; and in scheme 2, the UHV arrester with the rated voltage of 204 kV and 4 columns connected in parallel is selected. The difference between the two schemes is whether the beat frequency overvoltage on the neutral arrester should be classified as representative slow front overvoltage or temporary power frequency overvoltage. Finally, the scheme 2 is the final choice for the project although it is conservative, however, there are always disputes between the two schemes in the follow-up study of 1 000 kV double circuit transmission line. In order to clarify the dispute and provide technical basis of parameter selection for the neutral metal oxide arrester at neutral grounding reactor side, this paper puts forward the principle of selecting the parameters of neutral metal oxide arrester (MOA) and optimizes the parameters of scheme 1. Based on the analysis of the national standard definition of representative power frequency, the slow front overvoltage and the test standard of arrester withstanding representative overvoltage, the simulation results of beat frequency overvoltage for the power transmission project from Anhui province to the east parts of China by using ATP program are combined, and the basis of classification of beat overvoltage into representative slow front overvoltage and the criterion of neutral metal oxide arrester withstanding beat overvoltage are proposed. It is suggested that the optimized parameters of scheme 1 can be adopted for the neutral metal oxide arrester of 1 000 kV AC double-circuit transmission lines, which is beneficial to reducing the price of neutral arrester and the insulation level of neutral equipment, and to saving the project investment.