Two new methods for etching quartz glass by infrared-laser-induced chemical reactions of barium compounds are proposed, where the two barium compounds are BaCrO4 and Ba (OH)2,respectively. Via the deduction by the energy dispersive X-ray spectrometer and the analysis and test by the X-ray diffraction (XRD), it is found that micro-cracks and edges occur in the micro-channels obtained in the process of etching quartz glass by laser-induced chemical reactions of BaCrO4. Meanwhile, the decomposition of BaCrO4 produces BaO, which has a chemical reaction with SiO2 to generate BaSiO3 at high temperature, and thus this method can be used for etching quart glass directly. In the process of etching quartz glass by laser-induced chemical reactions of Ba(OH)2, both Ba(OH)2 and its decomposed BaO have chemical reactions with SiO2 at high temperature to generate BaSiO3, and thus this method can also be used for etching quartz glass directly. Different etching mechanisms for these two methods lead to relatively obvious difference of etching quality.