Isothermal, kinetic and thermodynamic studies of the adsorption of erythrosine dye onto activated carbon from Periwinkle shell was carried out. The Periwinkle shell were washed, dried, carbonized at 400oC, crushed, sieved, chemically activated at 800oC, cooled, washed and dried at 110oC. Variable influencing factors, such as contact time, temperature and concentration were studied through single-factor experiment, while other factors are kept constant (at 30min, 30oC and 50mg/L) in each adsorption experiment. From the adsorption isotherms, the correlation coefficient for Redlich-Peterson is closer to unity than others used in the adsorption. The adsorption kinetic followed pseudo-second order reaction, while the thermodynamic parameters, (∆H) = 13.49KJ/mol, (∆S) = 43.48J/mol.K and (∆G) = 0.4, 0.06, -0.15, -0.27, -0.54, -7.30KJ/mol. These results obtained show that activated carbon from Periwinkle shell will be a good low-cost adsorbent for the removal of erythrosine from aqueous solution.