Abnormality of geomagnetic pulsations was observed at Kashi region in Xinjiang before each of 8 earthquakes taking place from Nov. 17 to 29 in 1996. In this paper observation background and normal pulsations without earthquake are analyzed,abnormality of geomagnetic pulsations before earthquake is studied, and generation mechanism of the abnormality is discussed. This kind of pulsation abnormality before earthquake can be used in short bine prediction.