China's water resources mainly exist in surface water ecosystems and groundwater ecosystems such as rivers, lakes, reservoirs, and swamps.

The river ecosystem mainly includes Songhua River, Liaohe River, Haihe River, Yellow River, Huaihe River, Yangtze River, Pearl River, etc .; freshwater lake ecosystems include Taihu Lake, Poyang Lake, Dongting Lake, Hongze Lake, Chaohu Lake, Honghu Lake, Nansi Lake, Baiyangdian Lake, Huhu Lake Lun, Changbai Mountain Tianchi, Jingbo Lake, Dianchi Lake, Bosten Lake, etc.

Due to the influence of natural conditions such as climate and topography and socioeconomic conditions such as large population, China's water resources present the following characteristics:

The total amount of water resources is relatively rich, but the per capita and acres of cultivated land are small. China's annual average total precipitation is 6,058.4 billion cubic meters, equivalent to a depth of 643 millimeters. The average total water resources for many years is 2,774.1 billion cubic meters, ranking sixth in the world, of which the surface water resources are 2,696.9 billion cubic meters, equivalent to a runoff of 282 mm, and the groundwater resources are 808.7 billion cubic meters. China has a vast territory and a large population, with a per capita water resource of 2,200 cubic meters, which is only a quarter of the world average. The average water resource per acre of cultivated land is 1,440 cubic meters, which is 60% of the world average.

The spatial distribution of water resources is uneven and does not match the layout of productivity. Water resources are scarce in the north, and water resources are abundant in the south. The area of the six water resources in the north (Songhua River District, Liaohe District, Haihe District, Huaihe District, Yellow River District, and inland river regions in the northwest) accounts for 63.5% of the country's population, 46.1% of the country's population, and 44.5% of GDP, The arable land area accounts for 60.5% of the country's total, but the total water resources only account for 19.1% of the country's total. The area of the four water resources in the south (Yangtze River, Pearl River, Southeast, and Southwest) accounts for 36.5% of the country's population, 53.9% of the country's population, 55.5% of GDP, and 39.5% of the country's arable land area. The total amount of water resources accounted for 80.9% of the national total.

The uneven distribution of water resources within and between the years has led to frequent droughts and floods. Affected by the southeast monsoon climate, China ’s precipitation distribution is extremely uneven throughout the year. Most regions have about 70% of the annual rainfall for four consecutive months. The southern water resources area generally appears from April to July, and the northern water resources area is generally Appears in June to September. China's water resources vary greatly from year to year. The seven major rivers generally have periodic cyclical changes in periods of high or low water. The ratio of water resources between high and low water years is 3.0 to 5.0 in the southern water region and northern water regions. Up to 10.0. The uneven distribution of water resources in time has caused drought disasters in the northern water resource area and floods in the southern water resource area, and also caused seasonal drought and water shortage in the southern water resource area.