Abstarct: Late Neoproterozoic Majerad igneous - mextamorphic complex baxsement with NE-SW trend is located in the 150 km southeast of Shahrood and north edge of the Central Iran structural zone. In the north of Majerad- passage some small scale igneous body of gabbrodiorite (with an outcrop area of approximately 15 km2) and several Middle Jurassic diabasic dikes were intruded in to the Majerad igneous – mextamorphic complex. Field observation and petrographic study show evidences of fractionation from gabbro to tonalite in these gabbrodiorits intrusion. The placement of these intrusion bodies in to the host marbles have been accompanied by skarn formation. Plagioclase, pyroxene (augite type), hornblende and biotite (main minerals), rutile, esfen, apatite, magnetite and zircon (secondary minerals) and chlorite, epidite, secondary esfen and iron oxides (secondary minerals) available in gabbradiorites and quartz diorite to tonalite derivatives. Granular, ophitic, subophitic and poikilitic textures are found in these rocks. Geochemical studies indicate that magma forming of these rocks has calc-alkaline nature and baxsed on tectonic setting differentiation diagrams they are within the range of calcalkaline basalts associated with intracontinental extensional tectonic setting (back arc). Investigating the trace and rare-earth elements patterns and chondrite-normalized rare earth elements show that is enriched in large ion lithophile elements (LILEs) and also light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs) and heavy rare elements (HREEs). The parallel patterns of the changes of rare earth elements and the high values of LILE in these diagrams, along with the main oxides patterns and ratio of incompatible and compatible elements, indicate the same origin of the of grabbrodioritic rocks studied and the role of crystallization in the evolution of magma origin of these rocks. According to geochemical and petrogenetic studies, calc-alkaline magma origin of the gabbrrodiorite rocks is characterized by a low-grade melting of about 10% of a mantle source below the mextasomatised continent with the primary nature of spinel-lazulite, in the depths of about 80 to 100 kilometers, in an intracontinental extensional tectonic setting. Geochemical evidence indicates the high crustal contamination of magma forming the Middle Jurassic generation of gabbrrodioritic rocks in the Majerd region during placement and magma rising.