Abstract:     The seismological observation has been made on seimographs at the Great Wall Station during the period of 271 days from March 30 to October 25,1986. Total more than 3000 seismic events were recorded, most of them are microseisms generated by breaking and fracture of ice layers, 4 are the shallow earthquakes in sea near South Shetland Islands, a M=8.1 earthquake occurred at Aleutan Islands on May 7,1986, and a M=6.4 earthquake occurred at South Sandwish Islands on April 14,1986.     There is a significant difference between icequake and tectonic earthquake. The seimic records on Nov.16,1986, provide an excellent case for distinguishing icequake from tectonic earthquake. The icequake is characterized by a sharp first motion, high frequency and rapid attenuation. So it is easy to distinguish the icequake from the tectonic earthquake by their first motions and waveforms.

Key words: seismological observation, icequake, tectonic earthquake, Great Wall Station