Abstract: Strong earthquakes occurred frequently in North China area in history,but it showed tranquil since 2000.In order to analyze this phenomenon,we studied the joint area of Shanxi,Hebei and Inner Mongolia,the joint area of Hebei,Shandong and Henan province,Tangshan earthquake region, Yinshan Mountain and Yanshan Mountain earthquake belt with linear probability method that based on spectral analysis of earthquake.The results show that the method has prediction ability in some extent,and the ability is tested with R-value.