In this paper, the current situation on the study of water required for ecology and environment is summarized aiming at the maintenance of the view and ecology of landscape river in the affluent water area, to bring forward the calculation method of water required for ecology and environment of landscape. The authors put forward a point of view that the water required for ecology and environment of landscape is the water to keep the integrity of structure and function of river ecology and circumjacent landscape. In calculation of the water required for ecology and environment of landscape, firstly, the relation of river creature posture and wade wet cycle during some period should be studied to ensure the relation of water area dimension and river ecology system. Secondly, a key cross section is chosen to estimate the relation of water level and downstream landscape through referring to historical data, compute the relation of water level and runoff and it can fix on the relation of downstream landscape and water level at a key cross section. Finally, the authors adopt a method of mace-attribute decision-making analysis to make sure appropriate water required for ecology and environment of landscape. For the sake of explaining above point of view, this paper gives an example of calculation of water required for ecology and environment of landscape for Lijiang River.