In this paper we propose an architecture for the development of Intelligent Virtual Environments for Training, which is based on a collection of cooperative software agents. The first level of the architecture is an extension of the classical Intelligent Tutoring System architecture that adds to the expert, student, tutoring and communication modules a new module which is called World Module. Several software agents compose each module. Moreover, the proposed architecture includes agents able to simulate the behavior of human students and tutors, as well as agents able to plan the procedures to be taught (given an initial state and a desired final state) prior to the tutoring process.