In order to investigate the heating stages and degradation of nine pieces of oracle bones unearthed from Zhouyuan, all of them were studied with X-ray diffraction, thermal methods of analysis, electron microscopy and micro-infrared spectrum. The results indicated that the analyzed oracle bones had been fired in different temperatures, it was one of the reasons of their degradation, after unearthed, they were rinsed by hydrochloric acid for removing scales, perhaps it was another reason of degradation. Among many methods for studying the heating stages of oracle bones, X-ray diffraction and scanning electron microscopy play important roles.