Abstract: Firstly，the article defined the scope of grain and the concept of grain self-sufficiency ratio，and analyzed Chinese grain self-sufficiency ratio. Then the article studied about the factors affecting Hainan Province’s grain self-sufficiency ratio in recent years from two respects of grain production and consumption. What’s more， according to national policy，the article also gave some suggestions on how to increase grain self-sufficiency ratio in Hainan Province by strengthening the prevention of natural disasters，accelerating the pace to construct basic farmland of high standard，promoting rural land circulation，reasonably arranging planting structure and guiding the consumption structure of residents to give references to maintain the grain security.