Using the low cost of lawny grass to remove methylene blue (MB) from aqueous solution was evaluated in the batch process and the fixed-bed column. The MB adsorption capacity onto CG (grass modified with citric acid) was 301.1 mg . g(-1) biomass, which was almost three times than that of RG (raw grass). The equilibrium could be explained as pseudofirst-order kinetic processes, and equilibrium time was shortened to 20 min (CG) from 40 min (RG). The adsorption equilibrium followed the Langmuir isotherm model. The desorption rate with 0.1 mol . L(-1) HCl was almost 90 %. Regenerated CG was reusable with a little decrease (only about 3.38%) in its adsorption capacity during six repeated cycles. In the fixed-bed column, the breakthrough point of CG begins at 183 BV, which was much higher than that of RG (56 By). The elution process was achieved in a very small HCl volume.