| By using the meteorological data from 48 weather stations during 1965 to 2014 and winter wheat growing period data in Hebei Province, selected the SPEI (standardized precipitation evapotranspiration index), taken the water requirements of winter wheat to replace the evapotranspiration in SPEI, has analyzed the drought spatial features in winter wheat growing period near 50 years, and initially discussed the causes of drought change characteristics.The results showed that: (1) Under the situation of without considering the light drought, the occurrence frequency of medium drought was the highest as (9.2%～10.4%）in winter wheat growing period, the heavy drought was the next as（5.7%～7.4%）, and the extreme drought was the lest as（1.8%～2.7%）.(2) The high occurrence frequency regions of above medium drought was located in Hengshui and Cangzhou at the early and middle growing stages of winter wheat , but the Handan was the higher occurrence frequency region at the middle and later stages. (3) The drought with high intensity and wide range was occurred during 1968～1968, 1971～1972, 1981～1982 and 2011 in whole wheat growing period, among them the drought was run through whole growing period in 1968, but other years were total for stage drought. (4) The drought intensity and drought range in whole growing period of winter wheat was assumed a decreasing trend at 0.01 significant level. This decreasing trend was close related with the decreasing of water requirements of winter wheat, also this decreasing trend was affected by the decrease of sunshine hours and wind speed. |