There are two oxidation states of chromium in the environment, Cr(III) and Cr(VI). Chromium(III) is easily precipitated and adsorbed by soils, contrarily, Cr(VI) that exists as Cr2O72- or CrO42- is more mobile and soluble than Cr(III). Since the toxicity and mobility of Cr(VI) are higher than that of Cr(III), the reduction of Cr(VI) to Cr(III) by applied composts could be a feasible method to reduce available Cr(VI) in soils. However, in alkaline soils, the efficiency of compost amendments to reduce the Cr(VI) availability is lower than that in acid soils. In this study, Fe(II) and sodium dithionite solutions were added into Cr(VI)-spiked soils and their effects on the decrease of availability of Cr(VI) were investigated. Two representative alkaline soils of Taiwan, Chingchung (Cf) and Taikang (Tk), were treated with K2Cr2O7 solution to reach the level of 0, 250, 500, and 1000 mg Cr kg-1 soil respectively. The soils then underwent three wetting-drying cycles at room temperature to mimic field conditions. Reductants, as electron donors, FeSO4, Na2S2O4, Fe(NH4)2(SO¬4)2, mixture of FeSO4 and Na2S2O4 (4:1 mol/ mol), or mixture of Fe(NH4)2(SO4)2 and Na2S2O4 (4:1 mol/ mol) were applied to Cr(VI) spiked soils. The application rates (number of equivalents) of reductants were 0.5, 1 and 5 folds of number of equivalents of Cr presented in soils. Distilled water were added into soil samples to reach water holding capacity, then soil samples were air-dried at room temperature. The Cr(VI)-spiked soil samples, with and without reductant amendments, were evaluated for the availability of Cr(VI) in soils with DOWEX M4195 selective ion exchange resin extraction method, and the Cr(VI) on solid the X-ray absorption near edge structure spectroscopy (XANES) was used to identify the species of Cr in soils. The results showed that the level of resin-extractable Cr(VI) in reductant-treated soils was lower than the level in the control of Cr(VI)-spiked soils, and the decrease of available Cr(VI) content in soil depended on the amounts of reductants added. Previous studies proposed that the S2O42- of Na2S2O4 with K2CO3 buffer solution was more stable than that without the buffered solution. In order to create an optimal pH condition to reduce Fe(III) of soils into Fe(II), the Na2S2O4 was prepared with 0.05 M K2CO3. The available Cr(VI) content decreased while the soil pH（about 8）decreased slightly after adding the buffered Na2S2O4 solution. The Fe(II) solutions were adjusted to pH < 1 to be more effective in reducing Cr(VI) into Cr(III). Although this reductant was most effective in reducing Cr(VI) into Cr(III), the pH of Cr(VI)-spiked soils decreased the soil pH to 3.5. In order to increase the efficiency of Cr(VI) reduction and alter the soil pH to neutral, the two solutions were mixed to a 4:1 (mol/ mol) ratio at pH between 1-6. The addition of the mixed reductants decreased by 67 %-72 % of the available Cr(VI) content in alkaline soils and only decreased the pH to 7.0-7.8. The addition of the Fe(II) reductants at pH 1.4 decreased the soil pH to 6.7. The mixed Fe(II) and Na2S2O4 at pH 1.4 decreased the soil pH to 7.0-7.2 and reduced more availale-Cr(VI) content than the Fe(II) reductants. The XANES spectra of reductant-treated soils indicated that the intensity of Cr(VI) peak was smaller than that of the control of the Cr(VI)-spiked soil. This observation suggested most of the spiked Cr(VI) was reduced into Cr(III).