Bamboo structures have a good performance like wooden structures. The flexural performance of glued laminated bamboo beams for bamboo structures were studied through ten large-scale beams tested. The study investigated the failure modes of bamboo beams, flexural capacity, cross-sectional stiffness and strain distribution. In test, four kinds of typical failure modes of bamboo beams include brittle fracture of the bottom fiber, compressive buckling failure at the top of the bamboo strips layers, stratified fracture and oblique tear of the bottom fiber. The control condition of the design load was the cross-sectional stiffness rather than the flexural strength according to the experimental results. The flexural elastic modulus of 10GPa is suggested to check deformation of bamboo beams in the design. The plane-section assumption of cross-sectional strain distribution along the height is verified for bamboo beams.