The adsorption of Rhodamine B from aqueous solution by Thespesia Populnea Bark(TPC) as activated carbon are studied through Langmuir Freundlich, effect of pH and kinetic models, the experimental data’s are fitted to the Langmuir and Freundlich isotherm. Gibbs free energy ( ) ,enthalpy ( ) and entropy ( ) are calculated for thermodynamic parameters. The effect of temperature variation study proved that the Rhodamine B dye absorption was endothermic and spontaneous .