Using the temperature and precipitation data from 117 stations in the three-north shelter forest program areas from 1960 to 2011, we compared the characteristics of climate change in the areas before and after the implementation of the project. (1) Temperature in the project areas during the years showed a significantly increasing trend with a warming rate of 0.346°C/10 a. The years from 1960 to 1977 were a relatively low temperature period; temperature increased from 1978 to 1995; and the years from 1996 to 2011 were a significant warming period. The warming trend generally manifested the north-south difference, and the areas for notable increasing temperature mainly concentrated in northern regions such as Inner Mongolia Plateau, Songnen Plain in Heilongjiang Province and Plain of Western Jilin Province. (2) The annual precipitation of the project areas overall showed a declining trend with a decreasing rate of 3.554 mm/10 a. Precipitation was less than normal before the implementation of the project. In the beginning of implementation, there was a slight increase, but after 1996, precipitation performed an obviously decreasing trend. The tendency rate of precipitation distribution showed an apparent east-west difference. Precipitation in eastern regions decreased, while in western regions it showed a widespread increase and in eastern regions like Heilongjiang Songnen Plain and Inner Mongolia Yinshan Mountain area there was a notable increase of precipitation. (3) Spatial variation of climate change was obvious. The main climate changing trend in western regions like Altay Region and Qaidam Basin, and in the east regions of Inner Mongolia, Hetao Plain and Songnen Plain was warming and wetting, while in other regions, such as Hulun Buir prairie, Daxingan Mountains and Nenjiang Plain in Liaoning Province, the trend was warming and drying.