Abstract:The air temperature in Northeast China Region, the base of China's heavy industry, has raised significantly since the 50's of the 20th century. For an analysis on the causes, Northeast China Region is divided into 29 districts by Thiessen Polygon Program. At the same time, the mean annual temperature in each sampling position is taken to represent the temperature of each district. Then the variation of the mean annual temperature of each sampling position is analyzed from 1951 to 1998 and the increasing rate of air temperature in the 29 districts is obtained through least squares method. Finally, a special subject diagram is created, which reflects different prospective increasing rate of mean annual temperature in the 29 districts. It is shown that the increasing rate of air temperature in some districts is significantly different from those of the others, and that the more human activities there are, more greenhouse gas that mankind has released and more industrialized the region is, the more significantly the temperature of the region is raised. However, the increasing rate of the regional air temperature is much redused near the ocean.