A combined experimental and analytical investigation of an adhesively bonded composite joint was conducted to characterize the fracture mode dependence of cyclic debonding. The system studied consisted of graphite/epoxy adherends bonded with EC 3445 adhesive. Several types of specimens were tested which provided the cyclic debond growth rate measurements under various load conditions: mode I, mixed mode I-II, and almost mode II. This study showed that the total strainenergy-release rate was the governing factor for cyclic debonding.