Coal power generation is the second largest water use industry in China; its fast expansion puts pressures on water resources; water use quota management is supposed to be a vital means in saving water for coalpower generation industry. This paper, based on benchmark energy efficiency level of nationwide coal power plants, uses multiple regression model to evaluate water use intensity and factors of unit power generation in coal power plants, and estimates the expected water saving quantity in accordance with the latest edition of Coal Power Water Use Quota. The suggested general water use quota has little push on motive of saving water upgrading for coal power plants. Total saving water may be 122 millions cubic meters in 2020 given all plants comply with the suggested quota, but could be up to 823 millions cubic meters if three northern China regions satisfy the quota where water resources are rare, while other regions reach a premium quota. Viewing from technical perspective, water saving quantity proportions of circular cooling, direct cooling and air cooling are 58.6%, 18.7% and 22.8% under differentiated scenarios. Water saving quantity in eastern and northern China is over 200 millions cubic meters, around one forth nationwide, 108 million cubic meters in northwestern China, and 53 million cubic meters in northeastern China, the least.