Abstract: Time Petri net is widely used to model real-time systems and to analyze system performance. Conflicts are important behaviors of Petri net and its expansion model. To solve conflicts is a key for analyzing model dynamic behaviors. Now, some conflict checking approaches are provided to check conflicts of some expansion Petri Nets which include stochastic Petri Nets, hybrid Petri net (HPN) and interval speed continuous Petri Nets(ICPN). But these approaches can not be used to check conflicts of time petri nets. Because time constraints are imported, then time Petri net’s enabling and triggering semantics are more complex than that of Petri net, and the conflict checking of time Petri net is more difficult than that of Petri net. For accurately calculating time intervals and probabilities of conflicts, delay time intervals of transitions are defined based on time constraints when transitions are durative enabling, and the soundness and completeness of this definition are discussed. An approach is proposed to check resources conflicts of time Petri Nets based on time and resource constraints. The approach availability is verified by an example analysis. The results show that applying the approach to check the resource conflicts of real-time systems based on time Petri net modeling is accurate and feasible.