This note is taken from an abstract presented at American Geophysical Union, Fall Meeting 2012. The new seismic data set in south Java resolved detailed structures of the southern Java forearc. The plate interface expressed as irregular surface in the western part and rather a continuous smooth boundary in the eastern area. This observation coincides with the higher uplift of the western part of the forearc high. Cluster of shallow earthquakes can be observed near the western part of Java trench. Deformation of the forearc high is more intense in the west compared to that in the east. This coincides with higher uplift of the western part of the forearc high, thus complicated the structures.