Abstract: In this paper, we review the biotic and environmental events by examining the trace fossi1 records in association with the'Big5' mass extinctions in Phanerozoic, including the transitions of Ordovician-Silurian, Frasnian-Famennian, Permian- Triassic, Triassic-Jurassic and Cretaceous-Paleogene. The benthic fauna reflected in the trace fossi1 records show a negative re- sponse to all of the'Big5' events, documented by the decreases in the ichnodiversity, burrow size, bioturbation depth, and ichnofabric tier. The behavior and food-feeding strategy of benthic fauna is found to vary among the'Big5' mass extinctions. The deposit-feeding strategy dominated after the mass extinctions during 〇rdovician-Silurian and Cretaceous-Paleogene transi- tions, whilst the suspension-feeding strategy dominated after the mass extinction during Triassic-Jurassic transition. Opportun- istic trace fossils, such as Planolites, and both the deposit- and suspension-feeding strategies dominated after the mass extinc- tions during Frasnian-Famennian and Permian-Triassic transitions. The benthic ecosystems, reflected in the trace fossi1 records after the mass extinctions during Frasnian-Famennian and Permian-Triassic transitions, changed from simple to complex pat- tern, from two-dimensiona1 to three-dimensiona1 ecospace.