Abstract: The reanalysis data of NCEP(National Centers for Environmental Prediction ) can be used as a new data source for monitoring anomaly preceding earthquake. The data of NCEP for one month before Xinjiang earthquake occurrence at 21 march 2008 was analyzed. It is found that the thermal anomaly occurred near the epicentral regions at 6 o’clock 18th February (UTCS) , then it continued and moved to the epicenter. At 18 o’clock 20th, the variation of temperature had reached 7 K and the abnormal area had covered the epicenter entirely, at last the anomaly ended at 12 o’clock 21th. It can be known that the thermal anomaly area keeps consistency with the fault distributing. The abnormal center will correspond with the future epicentral location. This maybe has some relation between the thermal anomaly amplitude and the earthquake magnitude. The obtained conclusion will be have some important sense for the earthquake forecast.

Key words: Xinjiang, NCEP, thermal anomaly, fault, earthquake