Abstract: Abstract: Evaluation of the agricultural land use environmental efficiency is an essential issue for building sustainable land use patterns with fewer agricultural inputs and lower environmental risk. In this paper, 1) nitrogen footprint (N footprint) and grey water footprint (GWF) were used to evaluate environmental effects (reactive nitrogen emission and non-point source pollution) of agricultural land use system at the regional scale; 2) the window type slacks-based measure (SBM) model based on undesirable outputs (pollution N footprint and non-point resource pollution GWF) was applied to calculate environmental efficiency of the agricultural land use system; 3) inputs and environmental risk reduction potentials were computed and evaluated based on the dual perspective of reactive nitrogen emission and non-point source pollution in an intensive agricultural area. The Qingpu District was selected as a study case for this approach. The results mainly show that: 1) There were significant spatial-temporal differences in using pollution N footprint and non-point source pollution GWF within Qingpu District. The pollution N footprint of agricultural land use system was between 2 805.59 t and 3 505.68 t in the period of 2006-2013. The annual total grey water volume for agricultural non-point source pollution ranged from 134 026.58×104 m3 to 152 833.70×104 m3 during the years 2006-2013, and its average value was 144 969.00×104m3. The negative effect of water environment under agricultural land use process was assessed by the indicator of water environmental pressure (WEP) at county level. The average value of WEP of agricultural land use system was 5.74. The high value of WEP suggested that the negative environmental effect of agricultural production increased. The spatial distribution of pollution N footprint and non-point source GWF in Qingpu District was higher value in the west but lower in the east in general. 2) According to the results of SBM-undesirable model, overall environmental efficiency of agricultural land use in Qingpu District remained at a low level, and its average efficiency was 0.669 in the period of 2006-2013. 3) The models of potential percentage reduction and potential reduction scale were built for evaluation of dematerialization and environmental risk reduction respectively based on the dual perspective of reactive nitrogen emission and non-point source pollution. The annual average percentage reduction of labor, fertilizer, mechanical power, pollution N footprint and non-point source pollution GWF were 32.21%, 25.70%, 38.21%, 12.32% and 32.18%, respectively. The average reductions of labor, fertilizer, mechanical power, pollution N footprint and non-point source pollution GWF were 8 104 people, 4 501.59 t, 27 928.44 kW, 381.04 t and 52 046.88×104 m3 during the years 2006-2013. Xiang Huaqiao had the highest percentage of environmental risk reduction among the 11 towns, while Baihe and Liantang had a larger scale of emission reductions at the same time. Therefore, Baihe and Liantang should be the key areas for agricultural resources conservation and pollutant emissions control within Qingpu District. The findings of this study can provide scientific supports for regional agricultural planning and policy-making.