Abstract: In this paper, based on the strong earthquakes data from 14th century, the spatial and temporal characteristics of the distribution of the strong earthquakes along NE and NW tectonic direction and the relationship between frequency and the sum of strong earthquakes have been discussed. It is found that various kinds of frequencies of strong earthquake series along the same tectonic line are correlated to each other and their linear relation may be represented as Ni-Ni-k/(1-b)^k It canbe used to provide reliable criteria for the prediction of moderate earthquakes.