Abstract：In order to measure the ground surface deformation that induced by L'Aquila Mw 6. 3 Earthquake in Italy on April 6,2009,two pass method is applied in the study of coseismic deformation. Firstly,two groups of ascending and descending radar acquisitions from ENVISAT ASAR are processed as the primary data and the influence on experimental results based on different phase unwrapping method is compared. Secondly,ASTER GDEM is explored in two pass method. Lastly,deformation maps about L'Aquila 6. 3 earthquake in radar line of sight direction are obtained successfully. Results have shown that the use of appropriate phase unwrapping method in DInSAR technology can improve the accuracy of the outcome obviously. With the correct data preprocessing,ASTER GDEM can be applied with two pass method in radar interferometry and it has great potential. Surface deformation of L'Aquila Mw 6. 3 Earthquake is mainly vertical displacement. Moreover,this kind of vertical displacement is mainly settlement.

Keyword：DInSAR;L'Aquila earthquake;phase unwrapping;two pass method;coseismic deformation;