For the lack of a data structure, Petri nets are not suitable for modeling systems such as Information Systems, where data have an effect on the system's behavior. In the High Level Petri Nets we set out here, tokens are replaced by entities which are described by means of a model closely related to those of the Database Theory. In order to take into account the values of entities, a precondition and an action may be associated to each transition. This data structure allows to define new nets' properties, which are analyzed by Program Theory techniques, whereas a lot of results provided by linear algebra remain valid. In addition, computation of invariants may be done.