Abstract: Efficient experiment of applying nitrogen, phosphorus and potassium to introduced potato “Xingjia 2” were carried out in Aojiang Basin of Lianjiang County in 2011. The results showed that applying nitrogen fertilizer had the best effect and could increase the yield by 65.3%, and applying phosphorus and potassium could increase the yield by 17.3% and 19.7% respectively. In this paper, fertilizer effect regression model was established by using the quadratic polynomial stepwise regression, the fertilizing quantity for the optimum economic and the optimum economic benefit of planting potato in Hengcha and Baoxi were obtained as follows: N 14.0 kg/667 m² and 18.0 kg/667 m² (172.5 kg/hm² and 270 kg/hm²), P₂O₅ 11.5 kg/667 m² and 9.0 kg/667 m² (210 kg/hm² and 135 kg/hm²), K₂O 18.0 kg/667 m² and 15.5 kg/667 m² (270 kg/hm² and 232.5 kg/hm²), and the optimum economic benefit 3333.67 yuan/667 m² and 3340.13 yuan/667 m² (50005.05 yuan/hm² and 50101.95 yuan/hm²) respectively.