Title:Using UML mapping tool to System reliability modeling LIN Xiaofan , DU Bin (Department of software engineering, Chengdu university of information technology, chengdu 610225) Abstract: Most reliability modeling techniques are based on reliability block diagrams, fault rees,Markov chains and various other elements. Such formalisms may not be familiar to system architects,product managers and software developers. They normally use Unified Modeling Language (UML) to describe systems.Consequently, there is inevitably a gap between the design process and reliability modeling that system designers are facing. This paper proposes a method which adopt UML mapping tool to fill the gap.The feasibility of our method will demonstrate by an example. Keywords: UML, reliability modeling, fault trees, Markov chains