Abstract: A large-scale grassland yield estimation system was established by using the 3S(RS, GPS, GIS) technology. With observations on the ground and satellites view confirmation or grassland expert system analysis, a GPS coherent receiving chip was used in the system and the traditional m-sequencer was improved. It realizes the information obtaining for grassland yield, and builds a grassland yield estimation system. The estimation by the system shows that the designed data interfaces work properly, the estimated results are well consistent with the measured results and the estimation accuracy is improved. The new system expands and stretches searching consequence as well as pasture view map information within small scope towards wide scope at deep level.