The two sides of Taiwan Strait possess endless coastline and abundant marine resources. However, the governments of all the past dynasties lacked marine awareness, and their policies failed to straddle the coastline which influenced the opportunities for the development of marine activities. The developments of marine policies of all the past dynasties could be divided into four stages: the birth of marine concepts (during the Spring and Autumn Period and the Warring States Period), the development of marine activities (during the Qin and Han dynasties, the Three Kingdoms Period, and the Six Dynasties Period), the peak of marine activities (during the Sui, Tang, Song, and Yuan Dynasties), and the decline of Marine activities (during the Ming and Qing Dynasties). The activities in each stage had influenced the trends of the marine cultures and the marine literatures. In the Song and Yuan Dynasties, the public and private sectors relied on the thriving marine awareness to develop marine technologies, to exploit the marine resources. It helped the marine activities at this stage prosperous, and developed abundant marine cultures and literatures. Most of the writers at this stage stayed in the coastal regions. They possessed abundant marine experiences, and their diversified literary styles and descriptions on ocean were applied in describing the atmosphere of a sea country, recording sea livelihood, praising marine traditions, and forming strong ocean images. The marine literatures at this stage were characterized by its considerable works in terms of quantity and quality. This paper follows the framework below to discuss the marine literatures in the Song and Yuan Dynasties: marine cultures in China ¡÷ marine literatures ¡÷ marine literatures in the Song and Yuan Dynasties. First, it analyzes the insights and developmental conditions of marine cultures, and discusses the developmental courses of marine activities of all the past dynasties so as to lay the foundation of the chapters on marine literatures. Then, it shifts the focus from marine cultures to marine literatures and investigates the definition and standard for comparing literary works, locating artistic characteristics, and sorting out divisions of development stages. After constructing the overall concepts of marine cultures and marine literatures, it further analyzes the marine literatures in the Song and Yuan Dynasties. It also examines the basic information of marine literatures in these dynasties, and connects it with the analysis on the contents of literary works of various writers. In the main body of the study, the works of important writers in these dynasties are discussed respective, and the emphasis is to present the characteristics of various writers. Then, it reviews the literary works of these two dynasties as a whole to analyze the natural ocean and overall atmosphere of cultural ocean presented by the marine literatures at this stage from a broad viewpoint. Lastly, it analyzes the overall artistic characteristic and the limitations in the form and contents of this work. This paper concludes its finding as followed: the comprehensive knowledge of the marine cultures can supplement the developmental insights of ancient maritime technology, construct the developments of classical marine literatures, propose the standard for identifying marine literatures, demonstrate the meanings of important works of marine literatures in the Song and Yuan Dynasties, and reveal the insights of natural ocean and cultural ocean.