This study was performed to investigate the degradation of Maxilon Blue GRL which is widely used as textile dye and whom existence in textile wastewaters cause major trouble to human and other livings health. Using reliable methods such as subcritical water oxidation (SWO) and ultrasonic assisted oxidation (UAO) methods for cleaning the textile wastewater is of great importance. In this context, Subcritical water oxidation and ultrasonic assisted oxidation methods were applied using homemade stainless steel reactor system and Ultrasound system for degradation of MBG in aqueous solution. TOC removal was measured to determine the efficiency of the process. Experimental variables were evaluated by Response Surface Method (RSM) and optimum parameters and theoretical equations were proposed. ANOVA results of SWO experiments show that utilized design was expressed by quadratic model. The properties of this model presented by ANOVA terms. Maximum TOC removal rates obtained by using SWO and UAO were 89.44 % and 24.85 %, respectively.  Obtained findings indicated the applicability of the performed methods in the degradation of wastewaters containing MBG.