Agricultural areas include a unique biological diversity which is the basis of human activities. Conservation of this biodiversity is therefore fundamental and requires an operational approach. Biodiversity can be related to three main functions: (i) patrimonial functions that concern the conservation of landscape aesthetic and threatened species, (ii) agronomic functions that are related to the resistance to biotic and abiotic stress, and production in cultivated ecosystems, and (iii) ecological functions that are implied in ecosystem functioning with specific habitats and species. Agro-ecological indicators have been built to help decision-making and evaluate the impact of farm practices on biodiversity functions in grasslands, crops and unproductive areas, from the field to the landscape scale. These indicators are designed with data on farm practices which are easily accessible for the non specialist. Indicator validation is carried out with relevant site data which are related to biodiversity (biotic indicators, species richness).