Abstract: Subtropical monsoon climate with plentiful rainfall provides abundant water reso urces for the economic development of Shenzhen. But the seasonal variation of precipitation causes a number of difficulties in making good use of such resources. Take account of aforementioned condition, the reservoir constructions for regulate of water should be want. The mean annual rainfall amounts to 1600-2000mm. The runoff depth shifts from 800mm to 1100mm by declining westwards in almost the same way, while the require ment of water resources decreases eastwards. Speaking of water quality, it is excellent, except that of the Shenzhen river which has been seriously polluted by urban sewage.Although the quantity of water can fullymeet demand at present., but will be in short supply by 2000 yr A.D., in that time the population will reach 800,000. Groundwater, which deposits in the granite crack, can be exploited as auxiliary source. Efhcientmeasures must be taken in order to save mater, to effectively utilize local water resources and to improve waetr environment.