In this study, the corn husk was used as a low cost agricultural waste derived biosorbent to remove Cu (II) from the aqueous solution. The chemically modified corn husk was used to test for the efficiency on Cu (II) removal. Central Composition Design (CCD) of Response Surface Methodology (RSM) were used to study the optimization of adsorption efficiency by varying the parameters (initial Cu (II) concentration, biosorbent dosage and pH) by using the Design Expert software. The optimum conditions for the maximum adsorption capacity (89.11 mg/g) were obtained at 55.64 mg/L of initial Cu (II) concentration with 0.053 g of biosorbent at pH 5.38 whereas for removal efficiency (91.13%) is at 55.90 mg/L of initial Cu (II) concentration with 0.082 g of biosorbent at pH 6.35. Langmuir and Freundlich Adsorption Isotherm Models were analyzed to study the adsorption process. The equilibrium data fitted well with Langmuir model with R2 of 98.83%. Characterization of raw and modified corn husk before and after adsorption were analyzed using FTIR, SEM and EDS.