Radiolarians are a siliceous microorganism inhabiting the shallow to deep-water depths of the world Ocean and their fossil have the potential to be a powerful paleoenvironmental proxy providing us ecological information about the water masses from sallow to deep water depth. One of my research consists in clarifying modern radiolarian species ecology by analyzing modern samples such plankton tows, surface sediments and sediment trap for try to understand their species spatio-temporal distribution. My second research objective is to use the knowledge obtained from modern studies to estimate the response of marine fauna to the earth climate changes during the Cenozoic analyzing deep-sea core sediments. When trying to reconstruct paleoenvironment of old time period, we have to consider the ecology of extinct species, which are unknown and thus hamper the reconstructions. My third objective is to try to solve this issue clarifying extinct species paleoecology for allow more accurate paleoceanographic reconstructions.