Abstract: The “3414” field experiment on nitrogen, phosphorus and potassium fertilization were carried out in a rice field in Yubei of Chongqing. With the field test data, we established the fertilizer effect function of local paddy rice, analyzed and got this conclusion: to the rice with middle-level soil fertility, the best economic output is 642 kg/667m2; the best fertilization of nitrogen, phosphorus and potassium is: N 5 kg/667m2, P2O5 3 kg/667m2, K2O 4.5 kg/667m2; the appropriate ratio between the three fertilizers was: N: P2O5: K2O = 1.0: 1.0: 1.5. Meanwhile, the experiment also indicated that nitrogenous fertilizer was the most remarkable than the phosphorus and potassium fertilizer in the three factors of impacting the rice growth. The results were useful in choosing variety of fertilizer, the ratio and suitable quantity.