This mega thrust earthquake of Dec 26, 2004 shifted several sites on Indian and Eurasian plates, which has been quantified from various GPS studies. As the relative change in triangular area between different sites is more sensitive than the relative change in their coordinates, it has been attempted to calculate the anomalies in triangular area on daily basis between 12 permanent GPS stations of C-MMACS and 16 IGS stations for a period of 60 days from 1st Dec 2004 – 30th Jan 2005.