Potential biodiversity index (PBI) is an indirect composite indicator which aggregates ten key factors for which relations with forest taxa are established. PBI is relevant at stand scale and concerns only taxonomic biodiversity. A scoring system was developed with the aim to give a score directly in the field, without complex measurements, in an average time of 10 to 20 mn/ha. It differentiates sub-score for a set of 7 factors connected to the stand management and subscore for a set of 3 factors connected rather to the forest station. PBI is a tool for forest managers who wish to integrate easily ordinary taxonomic biodiversity in their everyday management. It is also a teaching aid which contributes to the evolution of forestry diagnosis and practices. PBI was built by using scientific literature and expertise of numerous specialists in taxonomy, and also with the collaboration of a wide diversity of potential users. PBI is included in the French national strategy for biodiversity and environment ministry provides financial help to a wide program of communication and training. PBI is already used by owners, managers of production forests but also of protected areas, advisers, logging companies, experts and also researchers. We realized more than 800 PBI diagnoses in a wide range of forest types throughout the France. PBI reflect structural variability of French forests and also it seems to be sensitive because forests which have not been logged for several decades received scores higher than managed forests. Moreover, we are calibrating the PBI with a pluritaxonomic approach by using a database which contains roughly 500 plots.