Abstarct: The studied area is located in the southern part of the Alborz mountain range and northern part of the Tehran city. The deformation of rock units such as folds, faults, and joints are investigated in the study area. Karaj Formation which belongs to Eocene epoch is affected by a variety of tectonic processes; therefore, exhibits various degrees of folding and faulting in many localities. Longitudinal faults of the study area have NW-SE trends (EmamzadehDavoud, F1, F3, and F4 faults) and mainly display a Strike slip and right lateral mechanisms. Latitudinal faults in the area have NE-SW trends (F2) also demonstrate a reverse left lateral mechanism. Axial surfaces of a major number of the folds in the area have a NW-SE trend. baxsed on the interlimb angle of the foldings, they are classified as open and tight. In addition, folds are classified baxsed on to their dip of the axial surface and the hinge plunge. Accordingly, 5 types of folds are recognized as (a) sub-horizontal- steeply inclined; (b) upright- moderately plunging; (c) gently plunging- steeply inclined; (d) upright- gently plunging, and (e) moderately plunging- steeply inclined. The geomorphological aspects is greatly affected by the structural elements (i.e. faultings and foldings). Joint reviewed are often dip 45 to 70 degrees. The joints relation with fold includes a transverse and two oblique category. In Darakeh anticline there are two transverse and one longitudinal joints category and Emamzadeh Davoud syncline includes a longitudinal and a oblique category. laxyers of the same gender, by increasing the thickness, the distance between joints will be increased.