Abstarct: In this research, fractures in the limestones of the Delichy and Lar formations in north-east of Shahrood city have been investigated. According to the obtained results these fractures can be classified into two categories with northeast – southwest and northwest –southeast trends which both formed due to deformation phases at different geological times. Some of these fractures have been formed during folding and others formed due to faulting. In addition, eight faults (F1 to F8) which identified in this research have geometrically the mentioned trends. Moreover, the effects of old and new slickenlines of paleotectonics and neotectonics-quaternary have been identified on these fault planes. The Quaternary movement may be identified with horizontal and young slickenlines that printed on slickenlines with rack of about 90 degrees. The evidences for identifying the Quaternary movement on faults is derived from the obvious signs of the Quaternary movement in the sedimentary –tectonics units in various regions of Iran including eastern Alborz. For example, faults with similar trend to east Alborz may be mentioned such as Astaneh and Shahrood Quaternary Faults which include strike-slip mechanism. The effect of the Shahrood Quaternary fault from the west of Shahrood to the northern part of Damghan with an approximate length of 60 km can be traced. baxsed on similarity in geometry of F1 fault with Shahrood Quaternary fault and its young strike-slip mechanism, it may be argued that F1 fault is a part of Shahrood Quaternary fault which extends from north of Damghan to carbonate formations Delichy and Lar in west of Shahrood.