Lusi is a mud volcano in East Java, Indonesia, which started its eruption on 29^th May 2006 and never stopped. To study this volcano, we used SAR interferometry with ALOS/Palsar satellite images from 2006 to 2010. By creation of a set of interferograms, and suppression of unwanted components, such as Earth curvature and elevation, we were able to compute the motion that occurred between two dates. The obtained set of motions shows that the region of Lusi is undergoing a general subsidence of several metres. However, as this region is very wet, more precise results, on the volcano itself, can be obtained by GPS campaigns.