The significant reduction of rural labor forces urgently requires light and simplified production methods. Direct seeding of rice is an efficient and economical cultivation mode, which is urgently needed by modern agricultural production. The low emergence rate caused by hypoxia stress under submerged condition is the primary factor hindering rice direct seeding. Identifying genes for tolerance to hypoxic germination in rice and developing submergence tolerant varieties are effective ways to solve this problem. This article reviewed the physiological characteristics, identification and evaluation methods, genetic analysis, and molecular mechanism of rice germinability under submerged condition. The results would be expected to provide theoretical reference for studying the molecular mechanism of hypoxia-tolerant germination of rice and selecting direct seeding rice varieties.