Abstarct: Ahovan area in the northeast of Semnan, is a part of south margin of the eastern Alborz. Stratigraphic studies illustrates that there are outcrops of Mesozoic and Cenozoic rock units in this area with northeast-southwest to east-west structural trend.Geomorphologic view of the studied area is highly affected by Structural features such as folds and faults as well as lithology. studied folds, baxsed on the interlimb angle of fold (Fleuty 1964), most of the folds fall with in open and gentle categories with a few in the close category. baxsed on the dip of axial plane and plunge of hinge line, the studied folds are classified into two domains, 1- Upright-horizontal, 2- Upright gently plunging. Folds in younger rock units such as Hezardareh conglomerate are very gentle and interlimb angle of these fold is large. Longitudinal fault strikes with northeast-southwest to east-west trend (South Rian, North Rian, Namord, Qarantul and Ebrahimabad) have left lateral reverse and left lateral mechanism. Transverse faults are visible in two major groups with north-south and northeast- nouthwest trending that include right and left lateral mechanism, respectively. Structures of the region are the result of palaeo and neotectonics phases. Such that old dip-slip movements (reverse) and the dominant slip movements are young. Young movements with stress field along the latest axis of maximum compression are compatible with N15˚E. Some of young and small faults in the Riedel shear model are related to larger faults and a number of large faults, are pre-existing faults, which according to their geometry have reacted differntly to the new tension field.