This paper focuses on aftershocks behavior and seismicity along some co-seismic faults for large earthquakes in Iran. The data of aftershocks and seismicity roughly extracted from both the Institute of Geophysics the University of Tehran (IGUT) and International Seismological Center (ISC) catalogs. Apply some essential methods on 43 large earthquakes data; like the depth, magnitude as well as the aftershock data; resulted knowledge about some relations between earthquake characteristics. We found ~16.5km for deep seated co-seismic fault length for the 2005 Dahouieh Zarand earthquake (MW 6.4) considering the dimension of the main cluster of aftershocks. Moreover, a slightly decrease in aftershocks activity was observed with increase in depth of the mainshocks for some Iranian earthquakes. Also the clustered aftershocks for the 1997 Zirkuh-e Qaen earthquake (MW 7.1) showed a clear decrease in maximum magnitude of the aftershocks per day elapsed from mainshock. Finally, we could explore an anti-correlation between aftershocks distribution and post microseismicity along co-seismic faults for both Dahouieh and Qaen earthquakes.