Corrosion of steel bars in concrete is a major problem reducing concrete structure lifetime that must be considered in the design of structures. Many parameters involved in corrosion propagation contain different uncertainties; therefore, probabilistic analysis should be performed. In this paper, we proposed a reliability analysis method for RC frames subjected to simultaneous corrosion and static loads. It consists of the analysis of an arbitrary 2D frame at each time step to take into account the steel bars mass loss due to corrosion. We calculated instantaneous load-bearing capacity of elements. Analysis outputs would be extracted, and the probability of failure and reliability index could be calculated in each time step. Moreover, we conducted the sensitivity analysis for some parameters. It is shown that various parameters such as cover thickness, dimensions, strength of materials and reinforcements how could improve vulnerability of concrete structure subjected to corrosion. We obtained outputs based on various corrosion models proposed by different researchers. Obtained results were compared with one another, and they have good agreement with experimental results in the literature. Proposed method shows that corrosion process could decrease strength of structural elements significantly.