Through the analysis of hydrochemical composition of natural water in Nushan Lake, the type and fundamental characteristics of hydrochemistry can be determined.The water is characterized by low minieralized degree and hardness, rich dissolved oxygen,and low alkaline pH.The type of water is C₁^Ca. Besides,through the compositive assessment of water quality in this lake, the following conclusions can be given; grade IV occupies great majority of the whole water area of this lake.Thcrefoe, the water conforms to many uses; drinking, fishery and tourism, etc.