Abstract: Miyun Reservoir on the Chaobaihe River is one of the main water suppliers for Beijing. Water and soil losses are the main reasons responsible for the reservoir sedimentation. The annual soil loss was estimated with a modified version of the Universal Soil Loss Equation (USLE). All the data necessary for model factors estimation were collected between 2001 and 2002 to form an analysis database. The factors in the model were computed and mapped using GIS and remote sensing. Based on the database, pixel-based computations were performed. This article analyzes the contribution of sediment yields on sub-units of the Chaobaihe river to Miyun Reservoir.