Abstract: Located in arid and semi-arid area,Ningxia is one of the climate change sensitive areas and ecological environment fragile areas in the Northwestern of China. Learning the characteristics of cloud water resource is very important for addressing the impact of climate change upon water resource. The data of Clouds and the Earth's Radiant Energy System(CERES)has higher spatial resolution and stronger pertinence,and is applicable to study of the characteristic of the cloud water resource in small scale terrain. With data of CERES and precipitation data from observation stations from June 2009 to June 2014,this paper studied the distribution characteristics and developing potential of cloud water resource in northern,central and southern regions of Ningxia which have different topography and climate characters. Results show as follows:(1)Atmospheric precipitation water in Ningxia region showed decreasing trend from southeast to northwest;and the volume of each season from most to least,in order,were summer,autumn,spring and winter. The difference of atmosphere precipitation water volume in each region was maximum in summer,followed by that in spring,autumn and winter.(2)The minimum value of total and low cloud covers was in northern region and the maximum value was in southern region under the influence of the East Asian monsoon and Helan Mountain terrain. The values of total cloud cover were from 26.3% to 26.7%,34.5% to 66.3% and 38.3% to 73.5% in north region,media region and the south region,respectively; The values of low cloud cover were from 23.5% to 55.8%,29.2% to 51.4% and 32.1% to 58.9% in north region,media region and the south region,respectively. The maximum of the total and low cloud cover were in September and July,respectively,and the minimum was in January.(3)The mean of the cloud optical thickness, water cloud effective radius and effective diameter of ice clouds were 9.16,10.4 and 43.7,respectively;the correlation between the cloud optical thickness and water cloud effective radius,effective diameter of ice clouds were significant negative and the strongest negative correlation appeared at north and central arid zones,particularly in the central Ningxia region,which is the most significant area for carrying out artificial precipitation. According to the spatial-temporal distribution of the artificial precipitation potential,it is suggested that we should intensify efforts for artificial precipitation in summer;the key areas of artificial precipitation should be carried out in the Helan Mountain and the central arid zone area in spring,the north of Tongxin County and south of Yinchuan City in summer,and Haiyuan and Xiji County in autumn.

Key words: CERES, cloud water resource, weather modification, developing potential