River network plain in Taihu Basin was selected as an experiment place, and triple duplication experiments had been carried out under artificial rainfall conditions to study the characteristics of phosphorus transfer from runoff of farmland. The results indicated that surface runoff was the main way of phosphorus losing from the agricultural field during artificial rainfall. The amount of losing phosphorus caused by surface flow and soil erosion of total phosphorus output accounted for 58.50% and 34.69% respectively, while that by interflow of total phosphorus output was only 6.81%. Particulate phosphorus was the primary pattern of phosphorus transfer which accounted for 60.73% of the total phosphorus losing. Inorganic phosphate was the primary pattern of dissolved phosphorus transfer. Compared with the particulate phosphorus, dissolved phosphorus can move more easily in the soil. Analysis of the characteristics of phosphorus transfer in surface runoff and interflow showed that soil could reduce the concentration of phosphorus when flows passed through it, in particular have obvious effect on reducing the concentration of TPP, up more than 80%. In addition, despite surface runoff was the primary way of phosphorus transfer in rainstorm-runoff process, in such a basin as Taihu, which has abundant rainfall, interflow is the main pattern at normal rainfall conditions, dissolved phosphorus transfer from interflow account for a large percentage of phosphorus loss, which has an important contribution to water environmental degradation of the region. Therefore it is of great significance to strengthen the research of dissolved phosphorus transfer for environment conservation.