The Paleozoic is a critical Era in the Earth’s history, starting from the Cambrian explosion and ended with the end-Permian mass extinction. It also witnesses several other mass extinction events (i.e., end-Ordovician and Late Devonian) and two dramatic ice ages (late Ordovician and Carboniferous-early Permian). All these biotic and climatic events are closely tied to global biogeochemical cycling perturbations and faithfully recorded in (bio)sedimentary records. This session aims to bring researchers from the globe to discuss the Paleozoic biogeochemical cycling and their (bio)sedimentary records. The topics may include, but are not limited to, microbialite and reef evolution, (bio)sedimentary records of the biotic and climatic events, continent weathering, and marine primary productivity and redox landscape of the Paleozoic.