Based on meteorological data and the data in the Geographic Information System (GIS) database of Nanjing area during the period from 2001 to 2008, soil and water losses in various districts, counties and small watersheds of Nanjing were quantitatively analyzed, with a new method for “quantitative monitoring of soil and water loss”. Results show that: (1) during the period, the area of lands subjected to soil erosion light or over was averaged 858.5 km², losing a total of 206.4×10⁴ t of soil; and the soil erosion occurred mainly in hilly areas; (2) the soil erosion was characterized by annual and inter-annual variations; which show that soil erosion occurred mostly from Apr. to Aug.; and it was the most serious in 2003, the least in 2001, and the closest to the average of the 8 years; (3) spatial variation of the average soil erosion existed among the districts, towns, and small watersheds; in terms of total amount of soil loss, and areas of lands subjected to light and serious soil erosion, Jiangning District ranked first and was followed by Liuhe District; and Baijia Lake and Shangba River were the most serious in soil erosion among the small watersheds; (4) the effect of the efforts of Nanjing to control soil and water loss was very significant; The erosion modulus declined from moderate to light, and the total amount of soil loss; the area of the lands subjected to soil loss and the area of the lands in urgent need for control areas all significantly decreased; and the area of the lands where soil erosion control measures had been implemented and the area of the land covered by vegetation increased, thus significantly improving the eco-environment of Nanjing; (5) the analysis of the effect of the control of soil erosion indicated that the increase in vegetation coverage and the implementation soil erosion control measures are effective in controlling soil erosion.