The relief patterns of photoresist grating in GaAs (100) plane substrate is produced by holographic interferometric exposure and photoresist development. The grating relief patterns of photoresist is then transfered to GaAs (100) plane substrate by preferential chemical etching. Gratings with a period of 0.33m have been successfully fabricated on GaAs (100) plane substrate and the grating corrugation has better V-shaped groove profile.