Abstract: The paper proposes a reliability measurement method with due consideration of the contribution of maintenance, to evaluate the reliability in a simple way. First, the RBD model is updated in case of maintenance, and is converted into the dynamic fault tree, then, the Markov transfer chain is used to analyze the reliability. An examples is given with these new methods. The analysis results show that the method can effectively measure the maintenance contribution to the reliability, and the analysis accuracy is better than that with the RBD.