Abstract: Mercury(Hg) and its compounds pose significant toxicity to humans, especially the organic species methymercury(MeHg), which can be bioaccumulated and biomagnified along the food chain. Rice (Oryza sativa L) consumption, which is grown in Hg mining areas and also in certain inland areas in Southwestern China, was the major source of MeHg exposure for inhabitants. Therefore, reducing the content of methylmercury in rice is crucial for protecting the health of populations in Hg-mining areas. Ridge tillage is a traditional agronomic practice, which has the advantages of water conservation and increasing yield. Ridge tillage can improve soil air permeability and affect the migration and transformation of redox sensitive elements in soil, and reduce the accumulation of heavy metals (such as arsenic) in rice. However, the effect of ridge cultivation on the migration of mercury in the soil-rice system remains unclear. To investigate the effect of ridge tillage on Hg accumulation in rice and Hg mobilization and transformation in soil, a field experiment was conducted in the Wanshan Hg mining district of southwestern China. The experimental treatments involved various ridge heights. The ridge heights were 7cm (R7), 10cm (R10), 15cm (R15) and 18cm (R18). The flooded treatment with conventional till (no ridge) served as the control (R0). The results showed that the change from conventional till to ridging rice cultivation patterns presented preferable environmental potential for inhibiting the uptake of both total mercury(THg) and MeHg in rice grain. After the application of different ridge height treatments, the ridge height of 10 cm (R10) treatment had the best effect on reducing the total mercury and methylmercury content in rice, and the total mercury and methylmercury content in rice were reduced by 21 % and 37 %, respectively, compared with the control. Ridge cultivation improved soil pH value and redox potential (Eh), and the soil pH value and Eh were significantly correlated with MeHg content in rice roots(P<0.05). As ridge height increases, the contents of MeHg in rice root for ridge tillage treatments (R7, R10, R15 and R18) significantly decreased by 46%～62% (P<0.05)., and this decrease was likely due to reduced MeHg concentrations in pore water resulting from ridge tillage. Specifically, ridge tillage treatments (R7, R10, R15, and R18) significantly decreased MeHg concentrations in pore water by 35%～70% compared to the control (P<0.05). Additionally, when compared with the control, ridge tillage treatments (R7, R10, R15, and R18) showed a decrease in the proportion of Fe-Mn oxide-bound Hg and an increase in organic-bound Hg. Among them, the proportion of Fe-Mn oxide-bound Hg decreased from 0.067% of control to 0.038%, and the proportion of organic-bound Hg increased from 66.4% of control to 79.8% in the R10 treatment. Furthermore, the oxide-bound Hg was positively correlated with the MeHg contents in rice grain (P<0.01). In conclusion, the ridge height of 10 cm in the paddy fields significantly reduced the contents of THg and MeHg in rice grain. These findings offer a theoretical foundation for exploring remediation strategies of mercury pollution in soil and reducing the risk of Hg accumulation in rice.