Compared with the versatility in metal industry, application of laser on oxide ceramics is quite limited due to the intrinsic features of ceramics and limited understanding in laser-ceramic interaction mechanism, especially for high-energy laser that causes melting of materials. In this research, a study into general behaviors of several oxide ceramics melted by laser under inert atmosphere is presented. Key factors in determining state transformation, chemical reduction and phase structure are summarized, with further investigation into the evolution in microstructure at multiscale and the corresponding novelty and metastability. It is found that laser melting does show great potential in introducing deep reduction, unique microstructure, and notable increase in structure complexity and total entropy, and those features could contribute to some unconventional functional performance with brand-new structure-property relationship.