The problem of describing the Be stars is especially interesting to investigate. A large collection of these objects are organized into information with preserving structures, such as classifications. In this case the difficulties consist of: 1) determining which are the main properties in the classification, and 2) deciding which one of the possible classifications should be used. For the first part there are a MK spectral system and a scheme of classifications presented by Jaschek et al. (1980), among others. The second part has been worked out in many ways. Here we describe, following the Information Theory (IT), an analytical method to compare both classifications of Be stars.