The globe climate change inevitably impacts the use of agricultural water. The distribution and change of blue water evapotranspiration and yearly irrigation water requirement of the four crops(maize, wheat, soybean and rice) in different regions were analyzed by using climate data of 93 meteorological stations in China from 1960 to 2009. The results show that annual average temperature increased by 1.1 ℃ from 1960 to 2009 in China. Northern China is warming faster than southern China, and climate warming has aggravated since 1980s. The blue water evapotranspiration of crop decreases at different extent;and the main influence factor of that was precipitation before 1990s, and that has been temperature since 1990s. The crop area of northeast China and Inner Mongolia increases significantly result from climate change, and the blue water requirement in these areas rises as well. The adjustment of crop planting structure between areas can relieve the pressure of agricultural water resources brought by the climate change in north China from the view of blue water evapotranspiration.