| Heilongjiang Province is one of major soybean growing regions in China but drought is a main part of meteorological hazards to its growth, which impact production security of soybean. For precise discriminating drought and enhancing the veracity of drought assessment, drought was studied in Heilongjiang Province based on drought index as continuous days without available precipitation. The drought was divided into five levels such as normal, slight, medium, severe and extreme drought by accumulated days of continuous drought. With these factors such as drought intensity, drought frequency and drought area, spatial-temporal characteristics of drought was analyzed during growing season of soybean. The results showed that center of high drought intensity located in the western Songnen Plain during growing periods of soybean from 1971 to 2016. During that period, the drought intensity was over 90 days in southwestern Songnen Plain, and there was obvious tendency toward increased drought intensity, which climate tendency rate was above 2.5 d·10a-1 in the northeastern Sanjiang Plain and the central part of Heihe region, and there was obvious tendency toward weaken drought intensity, which climate tendency rate was under -2.5 d·10a-1 in the southeastern Mudanjiang region. The medium of drought frequency was above 90% in the western Songnen Plain, and severe drought frequency was above 50% in the southwestern Songnen Plain. In the years such as 1976, 1979, 1982, 1989, 1999, 2001, 2004 and 2007 during the period of 1971 to 2016, drought above severe happened in eighty meteorological observation stations at 56% to 77% and soybean was still in a state of drought and water shortage was for three months. The drought extent and intensity in 2007 were the most typical. Dynamic change of daily drought frequency was characterized by the shape of “V”in growing periods of soybean. From sowing to flowering and podding stages of soybean, daily drought frequency decreased fewer than 40% from 60% to 90%, but daily drought frequency increased to 40% to 80% during emergence stage, again. Therefore, in Heilongjiang Province, as a concerd of soybean production security, the central region is better than the eastern part, and the eastern region is better than the west, and the northern part of the west is better than the southern part of the west. |