This thesis analyzes the lenticle quality of fresh water by choosing chroma, turbidity, chloride, COD and calcium ion as assessing indexes and assesses as the lenticle quality of fresh water using single factor method and Fuzzy Mathematical Method separately. The result shows that single factor assessing method is not compatible with the situation of the actual fuzzy margins water resources and that comprehensive assessing grade of the quality lenticular freshwater is category V. The compatibility of Fuzzy Mathematical Method with the situation of actual the situation of actual fuzzy margins of water resources is good with category I lenticular freshwater quality taking up 18.8%, category II 6.2%, category III 32.2%, category IV 2.8% and category V 40%. These data could provide technical reference for the practical utilization of lenticular freshwater.