The microstructural evolution and precipitation behavior of cryorolled Al 6063 alloy were investigated. The Al 6063 alloy plates were solutionized and cryorolled with thickness reduction of 25% and 93%. The phase identification and microstructure of the cryorolled Al alloy sample were carried out by XRD, electron backscattered diffraction (EBSD) analysis and TEM. The cryorolled Al alloy upon 93% thickness reduction exhibits ultrafine grain structure. The DSC results of cryorolled Al 6063 alloy obtained at different heating rate are used to calculate activation energies for the evolution of precipitates. The influence of different reduction rates on activation energy of precipitate formation in the cryorolled Al 6063 alloy was analyzed. It was clear from the present study that an ultrafine-grained Al 6063 alloy exhibits a higher driving force for the precipitation formation when compared to bulk Al alloy. (C) 2010 Elsevier B.V. All rights reserved.