Deadlocks are a constant issue in flexible manufacturing systems (FMSs). Circular wait is a necessary condition of deadlocks. In the framework of Petri nets modeling FMSs, deadlocks have a great relation with the resource circuits. In the paper, we present a symbolic approach to compute all resource circuits of Petri net models of FMSs by using binary decision diagrams (BDDs). BDDs can represent large sets of encoded data with compact shared structures and enable the efficient manipulation of those sets. Thus, the presented approach can efficiently find all resource circuits of a net model of an FMS. A number of examples are provided to demonstrate the proposed method.