Abstract: To overcome the disadvantage of traditional deterministic shear strength models for corroded reinforced concrete (RC) beams, a probabilistic model for shear strength of corroded RC beams was established. Based on the modified compression field theory (MCFT) and the critical diagonal crack angle model considering the influence of shear span ratios, a deterministic model for shear strength of corroded RC beam was established which takes into account the influence of reinforcement corrosion on various important factors such as the yield strength of transverse steel, stirrup reinforcement ratio, stirrup ratio, critical diagonal crack angle, sectional area of RC beam. Then a probabilistic model for the shear strength of corroded RC beam was developed by using the Bayesian theory and the Markov Chain Monte Carlo (MCMC) to take into account the influences of both epistemic and aleatory uncertainties. Finally, the applicability and efficiency of the proposed probabilistic model were validated by comparing it with the experimental data and traditional deterministic models. The analysis results show that the proposed probabilistic model is of good accuracy and applicability, because it can not only describe the probabilistic characteristics of shear strength of corroded RC beam, but also provide a benchmark to calibrate the confidence level and accuracy of traditional deterministic shear strength models.