In order to reveal the spatial variation of grain crop water requirement (W_R ) in the North China Plain under climate change, we downscaled the meteorological elements of RCP4.5 scenarios through the methods of SDSM, calculated the crop water requirement by Penman equation, and evaluated the water deficiency rates of piedmont plain, central alluvial plain and littoral plain through statistical methods. The results indicated that: 1) There was a strong relationship between crop W_R  and annual average maximum temperature. Under present climate conditions, a rise of 1℃ would increase the annual crop W_R  by 38.8 mm in Baoding, 44.8 mm in Dezhou, and 50.6 mm in Cangzhou. In RCP4.5 scenarios, the annual crop W_R  would increase by 29.1 mm in Baoding, 44.2 mm in Dezhou, and 39.6 mm in Cangzhou as the annual average maximum temperature elevates by 1℃. 2) From the current climate conditions to the RCP4.5 scenarios, there is an increase of crop irrigation water requirement (I_R)to different degrees, with the largest increase of 5.4% in Cangzhou and the lowest 4.8% in Baoding. Under the present climate conditions, the I_R is 717.14 mm in Baoding, 729.52 mm in Dezhou, and686.32 mm in Cangzhou. In RCP4.5 scenarios, the I_R is 751.50 mm in Baoding, 729.52 mm in Dezhou, and 723.64 mm Cangzhou. 3) From the present climate status to the RCP4.5 scenarios, thewater deficiency rates (W_a) of the piedmont plain and central alluvial plain will increase, while that of the littoral plain has the tendency of declining. 4) Under the present climate conditions, the annualaverage Wa(2011—2070) is 53% in Baoding, 47% in Dezhou, and 48% in Cangzhou. In RCP4.5 scenarios, the annual average W_a is 55% in Baoding, 49% in Dezhou, and 47% in Cangzhou. 5) Through building the evaluation index system of natural water deficiency rates, we can find that the highest level of W_a is greater than 50%, the medium level 30% -50%, and the lowest level less than 30%. 6) The probability density function (PDF) of W_a fits Weibull distribution well. Under the present climates, the highest level of maximum probability of W_a is 0.634 9 in Baoding, followed by Dezhou, 0.490 2, and the lowest in Cangzhou, 0.476 0. 7) In RCP4.5 scenarios, the maximum probability of W_a is at a high level in Baoding (0.698 2), and the next is at a medium level. In Dezhou, the maximum probability of Wa is also at a high level, reaching 0.515 2, and the next is at a medium level. In Cangzhou, the Wa of maximum probability is at a medium level (0.506 2), and the next is at a high level.