Abstract: The Mw 9.0 Japan Earthquake occurred in east coast of Japan in March 11,2011.Surface deformation process of Northeast area of China is inversed with the data of 6 GPS stations from CMONOC.Far-field cosesimic displacement filed of continental area of China is determined with the data of 160 GPS stations of CMONOC.The results indicate that cosesimic displacement of NorthEast area of China is the largest,on the average close to 20 mm,the average cosesimic displacement of Beijing and surrounding area is close to 10 mm,far-field area average is close to 5 mm,the major direction is east.This earthquake has no effect on South China(including the South China Sea) and the Qinghai-Tibet area of China.The results will be helpful for the research of dynamic characteristic of earthquakes and determination of the tendency of future earthquakes.