Abstract: Based on the classification of agricultural land productivity, the models of theoretical and accessible productivities per unit area of the cultivated lands in Weihe plain of Guanzhong were established, and the theoretical, accessible, and actual productivities of the cultivated lands in Liquan County were calculated, with township as a unit. In the County, the theoretical productivity of cultivated lands was calculated as 39.60×10⁴ t, accessible productivity was 29.82×10⁴ t, and actual productivity 18.69×10⁴ t. The theoretical, accessible, and actual productivities per unit area were 19071, 14745, and 9042 kg·hm^-2, the theoretical and accessible land use intensities were 0.764 and 0.639, and the theoretical and accessible production potentials were 4376 and 5115 kg·hm^-2, respectively. Spatially, there existed obvious differences in the theoretical, accessible, and actual productivities per unit area, being the highest in southern part, followed by in middle part, and the lowest in northern part. Terrain feature, soil type, input level, and technology were the main factors affecting the cultivated land productivity in Liquan County, and the southern and the middle parts of the County would be the key regions for the grain yield increasing in the future.

Key words: Shenyang area, Main tree, Potential of purifying SO₂, Quota of planting tree