Trust information is needed for both learners and teachers in virtual university system since both have their individual activities and reports stored in database. Their behaviors including the learner?s self regulations and the teacher?s/virtual campus regulations are performed and built with trust development. In this paper, we present an advanced Petri net model to manage the workflow of a web-based multiple participants in virtual university based on scaffolding theory. The presented approach can conspicuously help the developer not only to comprehend the interaction relationship between the client-server virtual environments but also to easily construct a shared and trusty virtual world. Problems of providing the multi-user interaction on the Web and the solutions proposed by the Petri net model are fully elaborated here. This paper can be used as a basic/fundamental research framework and tools to study and understand the characteristics of e-learning and to explore its optimal education application.