Abstract: Based on the observational data at the agricultural field and the daily meteorological data at 10 weather stations from 1980 to 2008 in Heilongjiang province, the temporal and spatial characteristics of main climatic elements and the impact of climate warming on soybean were analyzed by methods of a climatic variability, a Mann-Kendall test and a statistical regression. The results show that the warming trend is significant in the study area from 1980 to 2008. Annual mean air temperature increases; frost-free season extends and has the difference between different regions; heat resource increases significantly, especially in the south of Heilongjiang province. Hundred-grain weight of soybean increases with the increase of air temperature in September, while it decreases with the increase of annual mean air temperature. It suggests that the effect of warming in autumn on soybean yield is positive, while that of annual mean air temperature is negative. The effects of climatic warming on soybean yield are both advantages and disadvantages. Thus, it should be greatly considered for adjustment of planting pattern of soybean.

Key words: Heilongjiang province, Soybean, Climate warming, Yield