Abstract: Methane is an important greenhouse gas, but the rice field is one of the important sources of the methane. Therefore, it is important to study the discharge of the methane in the rice field. The mechanisms of methane produce, oxidation and transfer were elaborated in the paper firstly, and then laws of were summed up in day variation, seasonal variation, and interannual variation of the rice field methane emission. Influencing factors of the rice field methane emission were analyzed selectively, such as temperature, moisture content, organic quality of soil, Eh, soil pH , apply fertilizer, and so on.