Abstract: According to the reliability theory, the reliability design criterion and the design code, the performance function (PF) of the reinforced concrete bridge under the serviceability limit state (SLS) was deduced. It was based on the maximum crack width of the concrete bridge. The distributions of the variables in the PF were obtained and used to calculate the reliability index of the maximum crack width according to the point-fitting method. In the example, the reliability index was computed using the software Matlab, and it satisfied the code requirements. The sensitivity analysis was performed on the maximum crack width-based reliability index to examine the influence of the ratio of the live loads to the dead load.