Based on the forest resource survey data,we evaluated water conservation function and its spatial difference of Gonglongping state-owned forest farm by comprehensive method for water storage capacity assessment.It showed that 1) forest area of the forest farm was 3233.3hm²,with a total water conservation capacity of 3369.647×10³m³,and a water conservation capacity of 1042.17 t/hm² per unit.Water storage capacity of canopy,litter layer and soil layer of forest were 1244.936×10³m³,95.173×10³m³ and 2029.537×10³m³,respectively.2) Temperate coniferous forest,warm coniferous forest and evergreen deciduous broad-leaved mixed forest contributed 81.39% of water storage capacity of the forest ecosystem.In terms of water conservation capacity per unit area,warm coniferous and broad-leaved mixed forest as well as evergreen and deciduous broad-leaved mixed forest were the highest.3) Water conservation capacity in the forest farm showed an obvious spatial difference:in the western area it was the highest and significantly higher than that in the eastern and central areas,and in the central area it was the lowest.Overall,it will be a long-term goal of the forest farm to improve water conservation capacity.It is necessary to pay more attention to forest management and promotion of water conservation capacity by optimizing stand structure and improving stand quality.