In this paper, AlN powder and ceramic are prepared by microwave sintering under various sintering environments. The microstructures of the powder and the ceramic are characterized by scanning electron microscopy and X-ray diffraction technology. The mechanical and thermal properties of the ceramic are studied. It was found that the sintering environment has great influence on the material fabrication. The heat-assisted environment is beneficial to the synthesis of AlN powder. On the other hand, the carbothermal sintering environment has the two-sided influence to the sintering of AlN ceramic.