The influences of reinforcement corrosion on reinforced concrete beam failure modes are investigated. Experiments were carried out on 4 groups of the 21 reinforced concrete beams with different shear span ratio and different reinforcement corrosion degree. It is found that reinforced concrete beam specimens with the same longitudinal steel ratio and the same shear span ratio have three kinds of failure mode, i.e. bending failure, shear-compression failure and bond- shear failure along with the different corrosion extent of longitudinal and stirrups steel. Considering this phenomenon, and based on the experimental research and other related test results from literatures, a shear bearing capacity formula of corroded reinforced concrete beam that takes into account the effect of shear span ratio, corrosion ratio of stirrup and that of longitudinal bar, as well as the steel-concrete bond degradation, was established by utilizing the analytical concept of GB 50010-2010 code. Through the analysis and discussion of the critical conditions of failure mode transitions and the variation of general bearing capacity for the test beams, the analysis model of reinforced concrete beam failure transitions is proposed. Taking longitudinal reinforcement corrosion rate as the horizontal axis and stirrup corrosion rate as the longitudinal axis, according to the analysis model and considering the influence of shear span ratio and other factors to get the critical curve, the experimental results fit well with failure mode regions devided by the critical curve. The application of this model can make the preliminary judgment and control the damage form of the beam by different reinforcement corrosion rates.