Australia has significant security, defense and economic interests in the East Sea (South China Sea). Facing challenges to freedom of navigation, overflight, and uninterrupted lawful commerce caused by China’s illegal sovereignty claims and its dangerous actions in these waters, with a consis tent view, Australia has conducted diplomatic activities as well as operations on the ground to protect its interests. By pointing out Australia’s interests, the article clarifies its stance, diplomatic and opera tions on the ground to protect its interests, international law in the Sea.