Surface Modification of Activated Carbon from candlenut shell (Aleurites moluccana) was carried out with HNO3 to adsorb methyl orange dye. The manufacture of modified carbon goes through four stages, namely carbonization at 700 oC, activation with 10% H3PO4, and the last one is modified with 4N HNO3, and then pyrolysis at 300 oC. Modified carbon was characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). Various contact times were used to study adsorption kinetics and various concentrations were to study the adsorption isotherm pattern. The optimum time for adsorption of methyl orange dye was 40 minutes and the adsorption kinetic followed pseudo-second-order model. The modified candlenut shell activated carbon adsorption isothermal model follows the Langmuir isothermal model with the adsorption capacity value of 17.668 mg/g.