In this study, Cr2Nb-20 vol.% Al2O3 nanocomposite was prepared successfully by mechanochemical reaction between Al, Nb and Cr2O3 powders. Amorphization of powder occurred during mechanical alloying because of high energy collisions between powders and steel balls in milling container which transfer high degree of energy to powders. Therefore, annealing was needed to form crystalline phases. The influence of different mechanical alloying parameters such as BPR, rotating speed, milling time and PCA concentration on synthesis of composite material were investigated. After mechanical alloying, the powder was en-capsulated in quartz and then annealed at 1100 degrees C for 3 h. After annealing, 3 different phases were appeared (Cr2Nb (cubic), Cr2Nb (hexagonal) and alpha-Al2O3). The structural changes of powder particles during mechanical alloying were studied by X-ray diffractometry (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). (C) 2013 Elsevier Ltd. All rights reserved.