The nitrogen infiltration experiment was carried out indoors with the self-made device of the film hole infiltration to observe the distribution rules on nitrogen transportation and transformation under film hole irrigation.The total infiltration volume of film hole and nitrogen distribution in soil under different urea solution concentration were studied.The results show that the total infiltration volume increases with urea solution concentration.The urea solution concentration has little effect on the ammonium and nitric nitrogen distribution in soil profile,while obvious effect on their amount.The amount and the distribution of nitric nitrogen increase with the urea solution concentration.