Abstract: Pot experiments was carried to study biological nitrogen fixation and nitrogen transfer from peanut to rice in aerobic soil of intercropping system wi th two different methods: 15N-foliar feeding and 15N-isoto pe dilution methods. E vidence of nitrogen transfer was obtained in all of the two methods, which repre sents about 2.0%-3.5% of total N fixed by peanut. Root partition experiments al so suggested that the relative proximity of the root system of the associated tw o components is essential for increasing of N-transfer. The two methods gave id e ntical results. The advantages and disadvantages of the tow methods are also dis cussed in the paper.