The seafloor observation networks can achieve long-term and high resolution observation in such fields such as physical oceanography, chemical oceanography, geology, biology, acoustics and their interrelations. The seafloor observation networks have implications in various research frontiers of fundamental sciences, i.e. global changes, seafloor processes, land-sea interaction, ocean ecology and environments, and also offer services in state security and interests, marine resources development, marine calamity warming, marine ecological protection, marine engineering test, and marine sciences popularization. This paper mainly introduces the strategic objectives, sciences themes, and research advances of the Ocean Networks Canada, hoping to give useful inspirations and references for future construction of long-term seafloor observation networks in China.