It is generally known that the Chifeng-Kaiyuan fault functions as the boundary between the North China Block and Northeast Block.On April 22, 2013, the Tongliao M5.3 earthquake occurred in the central segment of the Chifeng-Kaiyuan fault, and thus, it exerted dual influence on the occurrence background in North and Northeast China.This earthquake was determined to be of mainshock-aftershock type based on the results of indicators such as the K value, G-R relationship, energy release rate R_E, and M-T.An analysis of the space-time evolution regularities of moderately strong earthquakes in Northeast China since 1900, presented in this paper, shows that earthquakes >M5.0 in Greater Khingan and the Songliao Basin are time-dependent and space-alternating events.Following the Arun-Oroqen border M5.3 earthquake of 2008, the Tongliao M5.3 earthquake occurred in the southeastern edge of the Songliao Basin as a moderately strong earthquake.Further comparative studies with past earthquakes in Northeast China have shown that this earthquake has both generality and particularity.The space-time evolution regularities of moderate and strong earthquakes in Northeast China, both before and after the 2011 Japan M9.0 magnitude earthquake, indicates that compared with other areas of Northeast China, the diamond-shaped area between the Hailaer Basin, Greater Hinggan transition zone, circum-Bohai region, and the Kailu Basin responded most strongly to the 2011 Japan M9.0 earthquake.Influenced by the Okhotsk M8.2 and Japan M9.0 earthquakes, more than eight M5.0 earthquakes occurred in the Songliao Basin in 2013.This article concludes that a new pattern of seismic activity is likely to start in Northeast China in the future.