Abstract: A fertilizer efficiency test was carried out in sweet potato field by using "3414" experimental design. The results showed that the maximum yield of sweet potato was 1690.6 (25 359 kg/hm²) when applying dosages of N, P₂O₅ and K₂O were 12.2 kg/667 m² (183 kg/hm²), 3.4 kg/667 m²(51 kg/hm²) and 16.6 kg/667 m²(249 kg/hm²) respectively, and the best economic benefit was 1688.85 RMByuan/667 m² (25 332.75 RMByuan/667 m²) when applying dosages of N, P₂O₅ and K₂O were 11.9 kg/667 m²(178.5 kg/hm²), 3.4 kg/667 m²(51 kg/hm²) and 16.0 kg/667 m²(240 kg/hm²) respectively.