Sr2CeO4 nanocrystallites were prepared by a sonochemical process with a later heat treatment using CeO2 and SrCO3 as source materials. The influence of processing factors on the phase composition and morphology of the crystallites were investigated. Results show that nano-Sr2CeO4 monophase could be prepared at the calcining temperature up to 800oC for 2h. Particle size of Sr2CeO4 crystallites decrease with the increase of ultrasonic irradiation power. Around 20-30nm Sr2CeO4 crystallites can be obtained at 800oC when ultrasonic irradiation power reaches 300W.