In this study, Cornulacamonacantha stem (CMS) has been used for the preparation of highly competent, ecofriendly and low-cost activated carbon (CMSAC) biosorbent. It was characterized by some instrumental techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The biosorbent was evaluated for the eradication of hazardous malachite green (MG) dye from aqueous solution. Batch experiments were conducted to assess the effect of various adsorption parameters such initial dye concentration, sorbent dosage, pH, agitation time and temperature. The results indicated that maximum sorption of MG was occurred at the pH ranged from 10.0 to 12.0. Langmuir, Freundlich and Tempkin isotherms were applied for the interpretation of experimental data and Langmuir model was found to be strongly fitted with higher R2 (0.999). The kinetics studies were examined using pseudo-first-order, pseudo-second-order, Elovich model. The sorption process was described by pseudo-second-order kinetics. The thermodynamic parameters such as energy change (ΔG°), enthalpychange (ΔH°) and entropy change (ΔS°) were found to be-6.21kJ/mol, 46.17 kJ/mol and 172.81 J/mol/K, respectively. The adsorption performance of malachite green dye onto gleaming activated carbon developed from Cornulacamonacantha stem was found to be spontaneous, feasible and endothermic process.