Understanding the state of biodiversity in a changing ocean is an indispensable step towards the sustainable management of marine ecosystem. The decadal achievement of Census of Marine Life promoted successfully at the data collection on biodiversity from world oceans and accumulated the data in the OBIS. While global synthetic analyses have suggested an extant of many ecologically or biologically significant areas in Western Pacific Ocean, inventories of regional biodiversity based on long-term observations remain insufficient. Biodiversity decline and habitats loss are crucial issues and we have to assess the present state and suggest the perspective of biodiversity in changing ocean. The project for observations and assessments of marine life started in Environment Research and Technology Development Fund (S-9). This project consists of six research teams to integrate with specimen-based approach, habitat-targeted approach and remote sensing approach. Data on marine biodiversity from coral reefs, seagrass meadows, kelp forests, pelagic water and deep sea, are collecting intensively in this project. These data sets are accumulated in BISMaL to analysis the changing patterns of marine biodiversity and identify what are risks for biodiversity decline. We will make recommendation for EBSA identification process and effective strategies on marine ecosystem management.