Abstract：The objective of this work was to investigate the effect of Al (III) on the reduction of Cr (VI) by organic reducing substances (contain phenolic hydroxyl and carboxyl groups) from sugarcane molasses, and to analyze the kinetics of Cr (VI) reduction in the presence of Al (III) under different conditions through batch experiments. Results indicated that Al (III) could catalyze the reduction of Cr (VI) by sugarcane molasses, and its mechanisms was organic reducing substances complexes of both Al (III) and Cr (VI) would reduce the reaction activation energy (Ea) of Cr (VI) reduction, and accelerated the reaction rate of Cr (VI) reduction by organic reducing substances from sugarcane molasses. This reaction could be described by the pseudo-first-order kinetic model with respect to Cr (VI) concentration in the presence of Al (III). At pH 2.0, 2.5, 3.0, and 3.5, the reaction rate constants increased 25.1, 13.9, 5.8, and 4.8h-1 respectively in the presence of Al (III) compared with that without Al (III). The reaction activation energy of Cr (VI) reduction by sugarcane molasses was 66.38 and 62.80kJ/mol respectively in the presence or no. When sugarcane molasses was insufficient, Al (III) would increase the removal efficiency of Cr (VI) reduction.