The leaching effects and main affecting factors were investigated for different leaching methods used in China and USA with chromite ore processing residue from an abandoned chemical plant，chromiumcontaminated soil and spiked leadcontaminated soil Results show that for the cations(eg Cr3+and Pb2+)，their leaching rates are mainly affected by their occurring forms，ionexchange of H+ and acid etching to solid matrix，and acid etching to solid matrix play the major effects，the lower the pH，the higher the leaching rates For anions(eg CrO2-4)，their leaching rates are mainly affected by ionexchange of OH- and acid etching to solid matrix which usually play more significant role than ionexchange effect Furthermore，leaching concentrations are affected by leaching rates and liquidsolid ratio，which might result in high leaching rates with low leaching concentrations