In this study, the performance of permeable walls that can achieve denitrification reaction by injecting H₂ gas was studied experimentally and theoretically. In laboratory-scale sandy aquifers, permeable walls were constructed with sand, gravels, and two other granules. Groundwater containing about 25mg-N/l of NO₃^- with some nutrient was fed continuously at various HRTs, and measurements of nitrate, nitrite, DO and pH were made over one year. Experimental results showed that all permeable walls could remove nitrate without accumulation of nitrite. However, the performance was different in four permeable walls. From this result, we found that the performance of permeable walls was influenced by the diameter of granule. We analyzed denitrification reaction rates using a mathematical model developed according to conventional mass balance and kinetic theory. The analysis showed that the denitrification performance of walls having relatively higher KLa value was lower than the model predictions. It was thought that these low performances resulted from plugging by microorganisms, as larger difference existed in higher biomass and higher dissolution rate conditions. Therefore granule in the permeable wall should be selected with consideration of volumetric mass transfer coefficient and plugging in walls.