Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious society.As mountain ecosystems play a key role in water resources conservation of mountain rivers,and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution,partition theory can be applied to the water resources conservation of mountain river.This theory observes the following partition principles:regional relativity,spatial continuity,integralcounty,meeting management needs,hierarchical principle,and comparability principle.And it lays equal emphasis on both water resources conservation and environmental protection,on both water quality conservation and water quantity protection,on the combination of water features,water cycle and water pollution.In the partition methods,index method and map superposition method will be applied in region partition.The example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers,and it provides a platform for future study in water resources conservation. Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient, and its level is far from being being able adaptable to the development of a harmonious society. As mountain ecosystems play a key role in water resources conservation of mountain rivers, and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution, partition theory can be applied to the water resources conservation of mountain river. This theory observes the following partition principles: regional relativity, spatial continuity, integralcounty, meeting management needs, it is lays equal emphasis on both water resources conservation and environmental protection, both of water quality conservation and water quantity protection, on the combination of water features, water cycle and water pollution. In the partition methods, index method and map superposition method will be applied in region partition. example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers, and it provides a platform for future study in water resources conservation .