Soil ecosystem is one of major reservoirs of microbial diversity on our planet. Many biological processes and interactions take place in soil, contributing to a considerable number of ecosystem services. Recent methodological advances, e.g. high throughput sequencing, provide an extensive knowledge on soil microbial communities in terms of diversity and composition. Thanks to these technological advances, numerous studies have investigated the variation of diversity indices and taxonomic composition of microbial communities according to changes in environmental conditions. However, estimates of microbial diversity through diversity metrics calculation such as Shannon, richness, evenness indices, etc, or determination of taxonomic composition through analysis of high throughput sequencing datasets do not provide information about interactions between community members, despite the importance of these interactions for community activity. In this context, the analysis of biotic interactions between microbial taxa is emerging in the field of environmental microbiology. First developed for the study of interactions between macroorganisms, the so-called “network approach” appears as a highly promising tool to better decipher the key role of microbial communities in soil ecology. In this presentation, we evaluate the advantages and the drawbacks of co-occurrence network approach to apprehend the microbial community modifications in response to environmental changes. We highlight that the connectance and the average degree of networks vary from 10 to 150% in response to moderate or chronic perturbations when microbial diversity remains stable. More precisely, our presentation is based on several applications revealing the sensitivity of microbial networks and associated metrics to detect changes in microbial communities such as: - Studies on a wide spatial scale (French territory) that highlight the significant influence of the level of anthropization (i.e. land use of soils) on the complexity of microbial networks - Assessment of the temporal dynamic of microbial network consecutively to organic matter addition that highlight a resilience of the network properties after strong changes occurring during the first steps of decomposition - Determination of the link between network metrics and community activity in terms of soil organic matter decomposition Altogether, our results evidence that microbial co-occurrence networks are ecological, operational and integrative bioindicators of ecosystem quality and functioning.