By using RS/GIS techniques and the method of multiple objective grey situation decision, and in considering the forest economic benefits (biomass and stand productivity) and ecological benefits (water and soil conservation), an optimal spatial allocation of the present forest types in Qingyuan County of Liaoning, Northeast China was approached in this study. After the optimization of spatial allocation, the structural proportions of different forest types in Qingyuan County changed obviously, with the area of coniferous forests reduced from 43% to 23%, the area of broadleaved forests reduced from 51% to 31%, the area of mixed coniferousbroadleaf forests increased from 3% to 43%, and the area of shrubs remained unchanged. As compared with the results before optimization, the biomass, stand productivity, and water conservation function of the forest ecosystem in Qingyuan County after optimization increased by 0.6%, 2.1%, and 31.7%, respectively, and the soil conservation function remained unchanged. It could be concluded that after the optimization of spatial allocation, the forest ecosystem of Qingyuan County could maintain its soil conservation function, and, at the time of keeping higher timber production, fully exert water conservation function, realizing the maximization of the economic and ecological benefits of the forest ecosystem.