Adsorption kinetics study of two Acid dyeing C.I. Acid red 198, C.I. Acid red 99 on cotton in absence and presence of cationic surfactant cetyl trimethyl ammonium bromide "CTAB" were carried out at pH 3.0, L:R 0.5 : 50 and an initial dye concentration 1.0 x 10^–4 mole dm^–3 Pseudo first and second order kinetic models were used to examine the adsorption kinetic data. It was found that the adsorption kinetic of two acid dyeing in absence and presence cationic surfactant with pH control was found to follow the pseudo second order kinetic model with an activation energy of C.I Acid Red 198 55.80, 57.65 and 40.04 kJ/mol but on C.I. Acid Red 99 44.28, 48.40 and 16.51kJ/mol. The effect of cationic surfactant on dyeability of cotton fabric with two acid dyes have also been studied at three different temperatures (45, 60, 90ºC). It was observed that the aggregation of surfactant and anionic dyes takes place at surfactant concentrations far below the critical micelle concentration of the individual surfactant