[Objective] This study was oriented to develop and establish a method for quantitative monitoring of soil and water loss that is applicable to both the northern and southern parts of the country and to provide a basis for scientific decision-making for regional ecological environment protection in the future. [Method] Based on the principle of the universal soil loss equation (USLE) and the large volumes of measured data of soil erosion and its relevant ecological factors in various soil and water erosion areas in South and North of China, the new method for quantitative monitoring of soil erosion was established using the "3S" (GIS, GPS, RS) technology. This method has been applied to a total area of over 300 000 km² covering Shandong, Fujian, Jiangsu, Yunnan, Beijing, Hebei and some other regions in China. Its application in Nanjing, Jiangsu Province is the longest in time and the most representative. During 1997-2015, this method was used in a long-term research to quantitatively monitor soil and water loss and soil erosion control in the entire Nanjing area. [Results] Results show that during the 19 years (1997-2015), the annual soil and water loss in Nanjing area reached 276.5×10⁴ t, and the average area light and over in soil erosion level did 863.7 km², accounting for 13.0 %. of the total area of Nanjing, only a small proportion, which, however, contributed, over 80% to the total loss, so it is still the key front of the battle for management of soil erosion and conservation of regional ecosystem; compared with the results of the monitoring before 2000 year, the area slight and over in soil erosion level were significantly lower in Nanjing area. [Conclusion] This method has its own algorithm and principle of model factors that are more consistent with the reality, so it is higher in accuracy and reliability. The monitoring with this method has validated that the city intensified its efforts in recent years to manage and control soil and water loss control and to supervise and manage the eco-environment in the area with remarkable achievements.