Abstract: In the light of realistic problem of lake water quality influenced by the increasing residual amount of soil nutrient, arising from the vegetable growing area and excessive fertilization in runoff area of Xingyun Lake, filed experiment was conducted to study the effects of fertilization technologies on onion yield and the changes of nutrient among soil layers before and after experiment. The results showed that the fertilization technologies had no obvious effect on onion yield, and the maximum onion yield was occurred in this fertilization technology (total 450 kg/hm2 nitrogen(N), 0 kg/hm2 P₂O₅ and 150 kg/hm2 K₂O; first using 10% nitrogenous fertilizer and 50% potash fertilizer as base fertilizer, then applying 20% nitrogenous fertilizer 15 days after transplanting, lastly applying 70% nitrogenous fertilizer and 50% potash fertilizer in the initial stage of onion bulb expansion). The residual amounts of soil available N in this layers(0-35 cm, 35-50 cm) were significantly raising with the increasing of application amount of N, however, the case was slightly decreasing in 50-75 cm. The residual amounts of soil available phosphorus and potassium in 0-35 cm were significantly raising with the increasing of respective application amount of P₂O₅ and K₂O, however, the case were slightly increasing among layers located under the cultivated horizon.