A model is formulated for calculating the reliability of gravity retaining wall corresponding to such failure mode as overturning,base sliding,insufficient bearing capacity of foundation and tensile strength of the wall,and a gradual equivalent method is employed to calculate the reliability of the structural system.The design parameters are assumed to be random variables with normal distribution,the random sample is extracted by using MATLAB library function normrnd.The reliability of several monadic failure modes and the reliability of the structural system are calculated by selecting a real retrofitted gravity retaining wall as numerical example and the result is compared with the theoretical analysis results made by author.The result shows that the reliability calculated from the two methods are consistent.