Abstract
The number of operations and states of a plan in multiagent system is finite, and the number of Coloured Petri nets element also is finite. Moreover, the action of plan is similar to the transition of Coloured Petri nets and the state or the resource of plan is similar to the place of Coloured Petri nets. Therefore plan can be modelled effectively by Coloured Petri nets. Consequently, the action, the state and the interaction of plan are modelled by Coloured Petri nets detailedly. Furthermore, the specification, validity and simulation of plan can be described by the theoretical techniques of Coloured Petri nets.