Abstarct: Bajestan granitoid pluton with an approximately 60 Km2 extension, located in the 3 to 12 km east of the Bajestan city. This pluton intruded in shale and sandstone (equivalent to Shemshak Formation with Jurassic age) and Paleocene volcanic and volcanosedimentary rocks. This granitoid has a compositional range from diorite, granodiorite, monzogranite, granite, alkali-feldspar granite, granite aplite and quartz-tourmaline veins and cut by a number of andesitic dike with the prevailing east-west trend. The essential minerals of this granitoid are orthoclase, plagioclase, quartz, hornblende, biotite, and tourmaline. According to mineralogy and geochemical characteristics, Bajestan granitoid belong to I-type granitoids has a mixed source of crustal and magmatic sources. In this investigation, for the first time, the emplacement mechanism of the Bajestan granitoid was studied in the light of the anisotropy of the magnetic susceptibility method (AMS). This pluton sampled in the form of cylindrical core at 86 stations, and we finally took 311 cores. After cutting and preparation, these cores were converted into 1786 pieces with 22 mm length. Magnetic parameters of these samples have been measured in the geomagnetic lab of Shahrood university of technology by using of the MFk1-FA model by using of magnetic susceptometer. The obtained data processed by Anisoft 4.2, StereoWin, ArcMap, Photoshop, Excel and etc. The summary of the results are as follows: 1.The average of mean magnetic susceptibility values (Km in terms of μSI) for the typical or candidate rocks of this Bajestan granitoids are as follows: diorites (9934), granodiorite (1008), monzogranite (797), quartz-tourmaline veins (148) and aplitic granite (122) and andesitic dikes (1633). Thus, diorites and aplites have the highest and lowest magnetic susceptibility, in respectively. The main magnetic carriers in the rock-forming of this pluton are magnetite, hornblende,biotite and ilmenite. Other minerals such as tourmaline, epidote, chlorite and a little oxides and hydroxides iron (derived from alteration) also have contribution in the magnetic behavior of the rocks. With respect to obtained data (magnetic susceptibility), this granitoid pluton belong to the ferromagnetic granitoids. baxsed on the interpretation of the concentration and the frequency of magnetic lineations and foliations, it is possible to suggest that most of the magnetic lineations and foliations have low plunge and dip (in respectively). The best lineation for all the rocks of the Bajestan pluton (except than andesitic dikes) is K1i/K1d = 14.2/13.1 and the best plane for foliation of the total rocks of the Bajestan pluton (except than andesitic dikes) is N3.9W / 11 NE. In some places, the plunges of the magnetic lineations and dips of the foliations are relatively high and usually correspond to the location of the dioritic outcrops or the feeder zone. The average trend of magnetic lineations was western-eastern trend, and in the northwest part magnetic lineations have lower plunges and in the south-east of this pluton, magnetic lineation plunges are a little more. According to the principles of the study of magnetic fabrics such as low plunge of the magnetic lineations and the low dip of magnetic foliations, emplacement mechanism of the Bajestan granitoids follow from a nearly dome-shaped structure which the roof or crown part of that has been exposed or cropped out.