In this study, the authors applied two-pass D-InSAR technique to process 15 JERS-1 SAR data. The final deformation field of Changbaishan-Tianchi volcano from 1994 to 1998 was expressed in 3 displacement maps which were obtained from 4 JERS-1 SAR data. The stuty achieves the following: firstly, the flat region far away from the summit of Changbaishan Tianchi volcano shows no obvious deformation; secondly, there is an increasing upward deformation from the foot of the mountain up to the areas at the elevation about 2000~oft-com:office:smarttags" />