Abstract: In this paper, by the statistical analysis of the path, source and moving velocity of the cold air, blocking high on the north of Baikal and Yakutsk was shown to be the main system of influence. We further analysed the reliability of the conclusion by the moving rule of the 500 mb five days mean anomaly centre, The centre of positive anomaly had been found active in the region before 5-10 days. We studied the relationship between the rule of transformation of ultra-long wave and blocking high by means of the barmonic analysis and the conclusions were as follows.