Abstract: The failure process in carbon fiber reinforces aluminium composite (C/Al) has been investigated by estimating tensile strength and acoustic emission behavior during loading combined with the analysis of the fracture morphology.The test specimens are cut from C/Al composite plates which have been prepared by using the diffusion bonding technique in air. Actnal dimensions of the specimens are 100 mm in length,6mm in width and 2~3 mm in thickness.