The largest historic magnitude earthquake of inland Iran occurred at 15H, 35M and 35.0S (GMT) on Sept. 16th, 1978. This event measured 7.7 in Richter scale and left behind over 15,000 casualties in township of Tabas, a tradition oasis at the edge of east Iranian desert. The area of total destruction extended for 1,000 km2 along the western foot of the Shotori Range. Other earthquake effects such as fresh thrust faulting, extensive land-sliding, stone up-throw and collapse of underground irrigation channels were observed within the mezoseismal area. A principal contraction to the east could be taken as the causative agent, which is in accord with the general tectonic regime of the area.