Based on the theories of landscape ecology, landscape eco-environment in the control watershed by reservoir of Erlong Mountain in Heilongjiang Province was analyzed and assessed by using GIS technique and statistical model of Principal Component Analysis and Spatial Cluster Analysis. It is found that 100.08km2( 36% ) of the total area is in the state of kilter, 85.73km2( 31% ) of the total area is in the state of general, and 47.26km2( 17% ) and 15.48km2( 16% ) is in the relatively poor state and ideal state. According to landscape ecological structure, there are three landscape function areas being planned and designed. 1) Agricultural landscape function area: its developmental direction is tour agriculture and high-benefit agriculture. 2) Eco-environment protected function area:the direction of development and utilization of this region is to develop vigorously forest for soil and water conservation, and try to increase the rate of vegetation cover. 3) Forest landscape function area: rational cut and utilization of forest resources, space optimization disposal of category of forest, foster of forest and protection of wildwood will become the main development directions for this region. This study trys to provide scientific foundation for ecological restoration of the whole valley and its sustainable development.