Ｔhe fabricating technology of Ar ion beam etching　for largearea　microlens array of 128×128 in ZrO2, InP, Si, and SiO2 substrates, was discussed in this paper. The experimental results showed that the experimental conditions of fabricating microlens array with the pdeterminating parameters in the different substrates were different. The experimental relations between the ionbeametching rate and ionbeam energy, and the SEM photograph of Si microlens array, were given.