Subsea production system has a broad application prospect in marginal offshore gas field development since its advantages in economy and efficiency， as well as its flexible development modes. Subsea production system and its common modes are introduced based on the summary of common development methods and their restrictions for marginal gas field development. The applicability of subsea production system in marginal gas field development is discussed. And a case study of development mode comparison and selection is conducted for marginal gas field development via subsea production system.