Abstract: Characteristics of temperature change and atmospheric circulation were analyzed in hot summer of 1999 and in cool summer of 2003 in Northern China.The results showed that obvious interdecadal variability of summer temperature was found,which was relevant to interdecadal variability of atmospheric circulation over the Asia.It also indicated that the important reason of summer temperature anomaly might be interdecadal variability of climate in Northern China.The circulation in mid-latitudes and high-latitudes in summer of 2003 took on two troughs and ridges,which was contrary to climate state of recent decades.The signs of climate shift were foreshowed in 2003 according to the characteristics of interdecadal variability.