Porous carbon having surface area of 792 m2g-1 was prepared from barley straw by carbonization at 800 oC at a heating rate of 5 oCmin-1 to test the chromium (VI) adsorption from aqueous solution. The effects of pH, contact time and equilibrium Cr (VI) concentration on the adsorption were studied in detail. The optimum pH for Cr (VI) removal was found to be 2. The adsorption of Cr (VI) was very rapid and equilibrium was reached within 1 h. It was interpreted in terms of adsorption-coupled reduction mechanism. Accompanied by the decrease of Cr (VI) ion, Cr (III) ion was slightly released in the solution. Maximum loading capacity of total chromium was found to be 2.35 molkg-1 at pH 2.