The EQ 26.12.2004, Mw=9, in South Asia was the strongest in the world for last 40 years since the Alaskan EQ of 1964. Time series retrospective analysis by two seismic moment tensor invariants of its source area for the period 1976-2004 and aftershock sequence investigation for first four months after EQ were executed. For retrospective analysis Ordering Index (0Kor1) and determinant of average seismic moment tensor matrix (DASMT) by the sampling interval were used. Ordering Index (Kor) can be considered as a measure of chaotization and high ordering phases of seismic process The value of determinant of average seismic moment tensor matrix from one side points out on dominated seism tectonic deformation mode in the considered space-temporal volume and from the other side on the fact is seismic process in this volume dominantly represented by double couple or non double couple (NDC) sources. Time-spatial aftershock’s distribution study based on the EQ catalog (~800 events, mb > 5) analysis.