Abstract: In this paper, through studyon earthquake distribution features and evolutional pro-cess of about 10 strong earthquakes occurred with different times scales in the eastern part of Northwest China region since 1900, we have found that there have existed the following law before strong earthquake in the region, i. e. there have existed longtermanomalous features of earthquake deficiency larger than 5 magnitude nearthe epicenters and mid-short-termanom a-lous features of rising of moderate-small earthquake activity level.

Key words: Strong earthquake, eastern part of Northwest China region, Tibet Plateau, Earthquake deficiency