Cadmium (Cd) has long been recognized as a serious health threat to humans. With 7% of the Chinese soil samples exceeding soil environmental quality limits, Cd is the most prevalent heavy metal contaminant in Chinese soils according to a recent report. Cadmium is also an important contaminant in food crops e.g. rice, especially in southern China. As a staple food, rice is a major source of Cd intake for large numbers of people in China. Environmental factors including redox and soil pH can change Cd availability in paddy soils greatly and hence impact rice Cd absorption. To understand the impacts of flooding duration and soil amendments on Cd speciation and release kinetics in paddy soils, a series of soil incubation experiments were performed. The soil samples used in this study were collected from Hunan Province, China (total Cd concentration 2 mg kg^-1, pH 5.8). All soil samples were spiked with CdCl₂ to achieve a final concentration of 165 mg kg^-1 to ensure the collection of high quality Cd extended x-ray absorption fine structure (EXAFS) data. Three g CaCO₃ and 1 g CaSO₄ were added individually and in combination. The soil samples were aged for 4 weeks, and then incubated under moisture conditions for another 2 weeks before use. Soils were flooded for 1, 7, 30 or 120 days in reaction columns, drained to field moisture capacity and then immediately collected or cultured for another 5 days and prepared for further analysis. A stirred-flow kinetic method was conducted to determine desorption of Cd from different soil samples. Synchrotron-based techniques and linear combination fitting (LCF) were employed to identify and characterize Cd speciation in the soil samples. The results show that increasing flooding duration and using amendments both decreased the maximum amount of Cd desorption and the rate coefficient significantly. LCF of bulk EXAFS spectra of different samples indicated that most of the Cd was sorbed on minerals, while an increasing amount of CdS was found as the flooding duration increased. Furthermore, high and low Cd rice cultivars were grown in a pot experiment with the two amendments used in the soil incubation experiment. The results show that both CaCO₃ and CaSO₄ treatments lowered the Cd concentration in rice shoot and grain, with more reduction with CaCO₃. These findings will aid in developing practical ways to reduce Cd accumulation in rice.