en Research Paper Research Paper In the present study, the effects of boron on the structural and magnetic properties of AlCrFeNiMnSiB_x high entropy alloys (HEAs) were investigated. In this regards, different percentages of boron element were added to the based composition and the samples were identified using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) methods. Based on results, the tendency of Si element to formation of silicide phases prevents from the stabilization of single FCC and BCC solid solution phases in AlCrFeNiMnSi alloy. The boron element has significant effects on destabilization of silicide phases and by increasing in the percentage of this element, the simple BCC solid solution phase has been dominate phase. Of course, boron has distractive effects on magnetic properties of prepared alloys and the saturation of magnetization of AlCrFeNiMnSiB_x HEAs decrease from 29.8 emu/g to about 6 emu/g by increasing the boron content.   High entropy alloy,Magnetic properties,Mechanical alloying,Annealing 1 9 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-1216-4&slc_lang=en&sid=1 Ehsan Tarighati E.TARIGHATI@GMAIL.COM 1800319475328460015095 1800319475328460015095 No Department of Materials Engineering, Malek-Ashtar University of Technology, Iran. Majid Tavoosi ma.tavoosi@gmail.com 1800319475328460015096 1800319475328460015096 Yes Department of Materials Engineering, Malek-Ashtar University of Technology, Iran. Ali Ghasemi ali13922009@yahoo.com 1800319475328460015097 1800319475328460015097 No Department of Materials Engineering, Malek-Ashtar University of Technology, Iran. Gholam Reza Gordani G.Gordani@gmail.com 1800319475328460015098 1800319475328460015098 No Department of Materials Engineering, Malek-Ashtar University of Technology, Iran.