In order to further reveal the change rule of water consuming structure in Fujian Province and based on the niche theory,this paper mainly adopted two kinds of ecological niche mathematical metric model such as niche breadth model and niche entropy model to carry out research．The results showed the ecological niche of agricultural water in Fujian Province declined significantly and that of industry water rose fast.While the ecology niche of domestic water had high stability which reflected that Fujian's industrial water in the eco-system element competition had a strong competitive advantage．Industry water rate in Fujian had a higher share than that in nationwide，but agricultural water and domestic water were on a lower level;The further optimization of water consuming structure is still an important problem for water resources management in Fujian Province.