Invited Papers -- Expressiveness and Efficient Analysis of Stochastic Well-Formed Nets -- Applications of Craig Interpolation to Model Checking -- Towards an Algebra for Security Policies -- Continuization of Timed Petri Nets: From Performance Evaluation to Observation and Control -- Full Papers -- Genetic Process Mining -- The (True) Concurrent Markov Property and Some Applications to Markov Nets -- On the Equivalence Between Liveness and Deadlock-Freeness in Petri Nets -- Extremal Throughputs in Free-Choice Nets -- A Framework to Decompose GSPN Models -- Modeling Dynamic Architectures Using Nets-Within-Nets -- A High Level Language for Structural Relations in Well-Formed Nets -- Derivation of Non-structural Invariants of Petri Nets Using Abstract Interpretation -- Modeling Multi-valued Genetic Regulatory Networks Using High-Level Petri Nets -- Termination Properties of TCP’s Connection Management Procedures -- Soundness of Resource-Constrained Workflow Nets -- High-Level Nets with Nets and Rules as Tokens -- Can I Execute My Scenario in Your Net? -- Reference and Value Semantics Are Equivalent for Ordinary Object Petri Nets -- Particle Petri Nets for Aircraft Procedure Monitoring Under Uncertainty -- On the Expressive Power of Petri Net Schemata -- Determinate STG Decomposition of Marked Graphs -- Timed-Arc Petri Nets vs. Networks of Timed Automata -- Specifying and Analyzing Software Safety Requirements of a Frequency Converter Using Coloured Petri Nets -- Achieving a General, Formal and Decidable Approach to the OR-Join in Workflow Using Reset Nets -- Tool Papers -- The ProM Framework: A New Era in Process Mining Tool Support -- High Level Petri Nets Analysis with Helena -- Protos 7.0: Simulation Made Accessible.This volume contains the proceedings of the 26th International Conference on Application and Theory of Petri Nets and Other Models of Concurrency (ICATPN 2005). The Petri net conferences serve to discuss yearly progress in the ?eld of Petri nets and related models of concurrency, and to foster new - vancesintheapplicationandtheoryofPetrinets.Theconferencestypicallyhave 100–150 participants, one third from industry and the others from universities and research institutions, and they always take place in the last week of June. SuccessiveeditionsoftheconferencearecoordinatedbytheSteeringCommittee, whose members are listed on the next page, which also supervises several other activities—see the Petri Nets World at the URLwww.daimi.au.dk/PetriNets. The 2005 conference was organized in Miami by the School of Computer Science at Florida International University (USA). We would like to express our deep thanks to the Organizing Committee, chaired by Xudong He, for the time and e?ort invested to the bene?t of the community in making the event successful. Several tutorials and workshops were organized within the conf- ence, covering introductory and advanced aspects related to Petri nets. Detailed information can be found at the conference URLwww.cs.fiu.edu/atpn2005. We received altogether 71 submissions from authors in 22 countries. Two submissions were not in the scope of the conference. The Program Comm- tee selected 23 contributions from the remaining 69 submissions, classi?ed into three categories: application papers (6 accepted, 25 submitted), theory papers (14 accepted, 40 submitted), and tool presentations (3 accepted, 4 submitted).