A dynamic process of the nonstructural carbohydrate translocation in rice plants is presented based on observation during one growing season. Differing amounts of nonstructural carbohydrates might be lost through rice plants due to the experimental plant manipulation. Relative to the CH\sb4 flux from the area of normal plants, significant increases in methane emission were observed in the area of manipulated plants. It is proposed that due to the experimental plant manipulation, more organic deposition entered the soil through rice plants than that under normal condition and, the lost nonstructural carbohydrate resulted in methane emission through the anaerobic methanogenesis in the rice field.