Abstract: A new evaluation method based on Weber-Fechner Law is used to assess the lake eutrophication and its integrate influence on people.The transparency(SD),CODMn,total nitrogen(TN),total phosphorus(TP),chlorophyll a(chl-a) are selected as the evaluation factors,whose weights determined by the entropy coefficient method are 0.1242,0.1768,0.2140,0.203 4,and 0.28161 The relationship between the entropy impact indexes(K_i) and the eutrophication indexes is also established.K_i standing for the connection of people's feeling with the changes of lake nutritional status,together with the nutritional status of lakes people.s satisfaction is classified into four levels:Better,normal,worse and worst according to the corresponding relationship between K_i values and its change rate with trophic indexes.The case study is conducted on Baiyangdian Lake in Haihe Basin of China.The results show that the average K_i value is 0.0523 and its change rate is 304.67,which suggests that Baiyangdian Lake is in the serious eutrophication status averagely.The people.s satisfactory level with the nutritional status of Baiyangdian Lake is lower.In different spaces of 8 locations of eutrophication from serious to better are as follows:Nanliu village > Quantou > Wangjia village > Zhang village > Shaohce lake > Zaolin village > Caiputai > Duan village.K_i values change from 0.029 3 to 0.10061 People's satisfactory levels are all worse,but exists the space diversity.