This work is within the scope of the development of a platform for virtual laboratory so practical work can be done from a distance on Web. It concentrates on the design and implementation of a generic prototype of a template to be used to describe a session of practical work. For this purpose we should make sure that all functionalities, that respond to the needs of instructors who are responsible for the creation of pedagogical content (editing, updating) and learner’s access to this template to do his/her practical work, are supported. We used UML [5] (modeling language) as a design language. We are able to develop a satisfactory and working result: a generic model, portable which offers to the principal actors involved in the teaching and training process (teachers, learners), a set of objects, a set of actions, and facilities which make it possible for each one to achieve his/her role.