This study investigated the plasma resistance of CaO-Al2O3-SiO2 (CAS) glass depending on composition. The glass compositions were selected by two methods; (1) glass compositions selected by conventional method around eutectic point and (2) known compositions in previous study (Choi et al., 2019). Also, the plasma resistance of each glass composition was examined by analyzing their surface microstructure and etching rate when the glasses were exposed to CF4/O-2/Ar plasma gases. There was no statistical difference in plasma resistance between two compositions groups. The CAS glasses showed 5-10 times superior plasma resistance compared to sintered Al2O3 or sapphire, where the etching rate of the Al2O3 and CAS glasses is 76.06 and 6.77-18.42 nm/min, respectively. Within the selected glassification range of the CAS-based glass, it was determined that the Al2O3 component most significantly affected plasma resistance. Glass compositions using conventional method can be more advantageous for glass fabrication.