The Polar Ocean is a repository of rich natural and biological resources. However, climate change, coupled with increasing human activities, have affected the keystone species and marine ecosystems of the Polar Ocean. The reduction in sea ice coverage has resulted in a decline in species such as krill, penguin, seal and polar bear, all of which rely heavily on sea ice in their lifecycles. One of the key objectives of scientific research in the Polar Ocean, as aligned with SDG14, is to ensure the protection and sustainable utilization of its environment and biological resources. This chapter reviews the current conditions and expected changes in the environment (temperature, salinity, water mass, sea ice, nutrients, trace elements), ecological processes (plankton, high trophic level species) and ecosystem services within the Polar Ocean. Furthermore, this chapter summarizes the research progress and outlines the future challenges associated with sustainable development of the Polar Ocean. The insights gathered above aim to provide vital support for the Polar Ocean in coping with climate change and human activities and ensuring the protection and sustainable utilization of the environment, resources, and ecosystem services, thereby contributing to the achievement of SDG13 and SDG14.