To provide aluminum nitride granules sintered at low temperature as the raw material for producing aluminum nitride sintered powder and a sintered compact at a low cost.

The spherical aluminum nitride granules having a mean grain size of 10 to 200 μm are obtained by forming an aluminum phosphate layer on the surfaces of the grains of aluminum nitride, further, forming an SiO2 layer on the upper layer thereof, and flocculating these grains. The aluminum nitride sintered powder is obtained by sintering the spherical aluminum nitride granules. In the method of producing aluminum nitride granules, a slurry aqueous solution comprising a phosphoric compound, a colloidal silica-dispersed liquid and aluminum nitride powder is spray-dried by a spray drier.