In the textile industry, the coloring process is done by dyeing the fabrics obtained from fiber, yarn or weaving, knitting and nonwoven surface methods. Waste water generated after dyeing processes contains dyestuff. Considering the situations such as the inability to reuse waste water and the damages it causes to the ecosystem; dyes should be treated. The treatment of dyestuffs from wastewater can be done by using different biomass by biosorption method. In this study, color removal from aqueous solutions of reactive group Remazol Red RR dye was investigated by using the biosorption method with sunflower biomass. Optimum values of parameters such as solution pH, amount of biosorbent, initial solution concentration, electrolyte effect, contact time and solution temperature were found by experiments. Color removal was found to be 70% under optimum pH 2 value, 100 ppm initial concentration, 0.1 g biosorbent amount, 60 minutes working time and room temperature conditions. Pseudo-First and Second Order Kinetic models, Langmuir and Freundlich models for adsorption isotherm were applied to experimental data. The biosorption of Remazol Red RR dye on sunflower biomass was compatible with the pseudo-second order kinetic model, Langmuir adsorption isotherm model and thermodynamic data were evaluated, it was determined that the biosorption occurred spontaneously with negative Gibbs free energy values.