Abstract: The analytic hierarchy process was applied to assess comprehensive benefit of 15-year Eucalyptus plantation with four different densities including 600、900、1 200 and 1 415 trees per hechare in the hill area of southern Fujian Province. The economical, ecological, and soil fertility maintenance values for the Eucalyptus plantation with different density were categorized by integrating eight factors involving stand stock, timber output, water holding capacity, biodiversity of underlayer, soil density, total porosity, organic matter and available fertility. The model with best comprehensive value was the tree density of 1 200 trees per hectare for Eucalyptus Plantation according to the assessing, which provided a reference for sustainable management of Eucalyptus plantation.