The effects of interfacial adhesion strength on the damage behavior and energy absorption characteristics of an aluminum (Al)/carbon fiber reinforced plastic (CFRP) short square hollow section (SHS) beam under three point bending loading was investigated. An Al SHS beam was wrapped by CFRP with a [0 degrees/+45 degrees/90 degrees/-45 degrees](n) (n = 1 or 2) stacking sequence, and four gradations of interfacial adhesion strength were caused by physical or chemical changes of the Al adherend with different mechanical abrasion and optimal Argon plasma treatment. A different level of appropriate interfacial adhesion strength existed for each hybrid specimen depending on the CFRP laminate thickness to obtain the highest energy absorption capability, and this was verified by detailed observation of the failure mechanism of the hybrid specimen. The specific energy absorbed (SEA) was improved by up to 57.2% in the Al/CFRP [0 degrees/+45 degrees/90 degrees/-45 degrees](2) SHS beam compared to the Al SHS beam without compromising the crush force efficiency (CFE). (C) 2014 Elsevier Ltd. All rights reserved.