The style of water use was restricted in a large extent by the fragile eco-environment in Ningxia and Inner Mongolia Autonomous along the Yellow River. Applying the runoff data and the field survey data, we analyze the main contradictions between water use and environment in this area. And by overlaying the meteorological data with the statistic data of soci-economy, we regionalize the ecologically geographical zones. We also analyzed the main style of water use based on the ecologically geographical zones. In conclusion, it is strongly proposed that harmonious relationships in water-man and water-environment systems have to be established to realize sustainable water supply in this area.