1,1,1-Trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) is one of the most extensively used organochlorine pesticides worldwide. As a result, DDT can be detected in various environmental compartments in recent years, and its concentration is much higher in the soil than in the air and water. Therefore, it is of great significance to develop an efficient technology to remedy DDT contaminated soils. Reductive dechlorination seems to be a crucial pathway for DDT degradation under anaerobic conditions, because the five electrophonic chlorine substitients in a DDT molecule make aerobic oxidative degradation difficult. However, reductive dechlorination requires the addition of two electrons for each chlorine removed. Therefore, the existence of electron donor substance and electron shuttle is vital to electron transfer, and hence may affect the reductive dechlorination of DDT in anaerobic reaction systems. In order to investigate reductive dechlorination rate of DDT in Hydragric Acrisols which is widely distributed in tropical and subtropical regions and contains abundant iron oxides; to examine single and interactive effects of n-butyric acid as electron donor substance and AQDS as electron shuttle on soil microorganisms degrading DDT; and to elucidate relationship between DDT dechlorination and methane generation rate, a batch anaerobic incubation experiment of Hydragric Acrisols was conducted. The experiment was designed to have five treatments, i.e. (1) Sterile control, (2) Control, (3) n-Butyric acid, (4) AQDS, and (5) n-Butyric acid + AQDS, and three replicates for each treatment. The treated samples in sealed culture flasks were incubated at 25 ˚C in darkness for 20 days. During the incubation, gases in the flasks were sampled once every four days for analysis of CH4 concentration, and soil samples, too, for determination of Fe(Ⅱ) contents, DDT and its degradation products, and oxidation-reduction potential (Eh) of the reaction systems were measured simultaneously. Results show that after 20 days of incubation, DDT residue in treatment 1, 2, 3, 4 and 5 decreased by 44.5%, 85.2%, 90.2%, 93.2% and 96.3%, respectively, as compared with the initial value. In terms of first-order kinetic constants (k) of DDT transformation, the five treatments displayed an order of Treatment 5 > Treatment 4 > Treatment 3 > Treatment 2 > Treatment 1. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane) was found to be the dominant degradation product of reductive dechlorination of DDT in the current assay. DDE (1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene) and DDMU (1-chloro-2,2-bis(p-chlorophenyl)ethylene) were also detected as the secondary dechlorinated products of DDT, though not much, and the former was higher than the latter. Some non-extractable DDT and its degradation products were detected to be bonded by soil organic matter and clay particles, and hence retained in the soil as residues, mainly in the first 4 days of incubation. During the first 8 days of incubation, Treatment 3 significantly increased CH4 generation rate, but did not do much DDT dechlorination. However, in the days later, with declining CH4 generation rate and rising Fe(Ⅱ) content, DDT dechlorination rate gradually increased in the treatment. The findings indicate that the amendment of n-butyric acid leads to completition for electrons between methanogenesis and reductive dechloriantion of DDT during the early incubation period, which is not conducive to reductive dechloriantion of DDT. The amendment of AQDS significantly increased soil Eh values and accelerated reduction of Fe(Ⅲ) oxides into electron-donor Fe(Ⅱ), thus promoting markedly reductive dechlorination of DDT, which indicate that the quinone moieties in AQDS molecules act as redox modulator promoting DDT dechlorination under anaerobic conditions. Treatment 5, the addition of n-butyric acid + AQDS, was the most efficient in accelerating reductive dechlorination of DDT, but in this effect, no significant interactive effect between the two was observed. The present study has demonstrated that the application of both electron donor substance and electron shuttle is an ideal approach to acceleration of DDT dechlorination in the soil, and the findings may have some important meanings for developing efficient in situ remediation technology for DDT contaminated soils.