The structured Petri net model is presented for the representation and analysis of the control structures of distributed computing system software (DCSS). The basic properties of the model and some analysis techniques using this model are also presented. Liveness, reachability, and other related problems and their complexity are investigated. The NP-completeness of the reachability problem of this model is demonstrated. Four subclasses of structured Petri nets are then identified, and within these subclasses more efficient analysis methods based on decompositions are developed. Several O(|T| and O(|T|)2) algorithms for liveness and reachability analyses are presented. Since most of these algorithms can be performed efficiently and economically, it is feasible that they be integrated as an analysis tool for supporting the DCSS development process.