Analyzing water balance of the ecosystem (area for collecting rainwater) in geomorphic unit and the hydrologic process, taking the rainwater allocation proportion, rainfall runoff volume, losing quantity of soil and nutrients in different sloping land ecosystem as parameters, considering the requirement of water balance of geomorphic unit in the area for collecting rainwater, irrigation in the sloping land, the bearing capacity to the rainwater erosion of different sloping land ecosystem and the influence of the rainwater travel from slopping land on the environment and the water-logging-disaster area as constraint condition, construction of agro-forest multi-ecosystem in hilly sloping land of red soil is fitted out with a view to water balance and reasonable land utilization structure: artificial afforestation is 30%, 15% for sown pasture, 30% for tea garden, 20% for cultivated land, and 5% for natural protection area. It characterizes as that it offers gist for construction of agro-forest multi-ecosystem in hilly sloping land of red soil with a view to water balance and suitable land utilization structure; it embodies the thought of great agriculture, corrects the tradition utilization of one unitary ecosystem in hilly slopping land; the proportion of land utilization accords with the development of social economy, can basically achieve the requirement of foodstuff security to plough land prolongation at the peak of population. This structure meets the requirement of which not only using slopping land to collecting rainwater for keeping water balance in geomorphic unit (area for collecting rainwater) ecosystem, but also the sustainable protection of agro-forest multi-ecosystem in the slopping land.