jgg     2014 34 (3):  43-47    ISSN: 0412-1961  CN: 21-1139/TG VARIATION OF GRAVITY-FIELD BEFORE AND AFTER  MINXIAN-ZHANGXIAN Ms6.6 EARTHQUAKE 1）Key Laboratory of Earthquake Geodesy,Institute of Seismology，CEA，Wuhan 430071 2）Wuhan Base of Institute of Crustal Dynamics,CEA，Wuhan 430071 3）University of Chinese Academy of Science，Beijing 100039 4)Earthquake Administration of Gansu Province,Lanzhou 730000 Received: 2013-12-12  Revised: null  Online: 2014-05-28 Supporting info