We report the fabrication of SiC nanocrystals via direct pyrolysis of polysilazane at 1350 ℃ for 90min in vacuum.The products were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM).The results suggested that as-prepared nanocrystals are 3C-SiC, and averagely sized in ~100hm with a uniform particle size distribution.The temperature dependent photoluminescence properties of the obtained nanocrystals ranged from-160℃ to 160℃ have been characterized, suggesting that our fabricated SiC nanocrystal can be a stable luminescent material against to the work temperatures.