The AlN powder was immersed in deionized water, HCl aq, NaOH aq and H3PO4 aq to investigate their hydrolysis behavior at 283 to 373 K. The pH of the solutions were not varied at the initial stage in the case of deionized water, and they increased abruptly after the incubation time with evolution of NH3. Time until the evolution of NH3 decreased with increasing temperature. The hydrolysis at the higher temperature was different from at the lower. Below 351 K a crystalline bayerite was produced on the surface of AlN particle, while a crystalline boehmite was produced at higher than 351 K. The AlN powder was hydrolyzed more efficiently in HCl aq and NaOH aq compared with in the deionized water. While, H3PO4 aq restrained hydrolysis of AlN powder.