3414 test results from 2007 to 2009 in Haimen of Jiangsu Province showed there were ternary quadratic regressions between rape yield and nitrogen, phosphorous and potassium use ratios, the regression equations of 2007 to 2008 and 2008 to 2009 were : y = 98.220 + 4.876N - 0.231N2 + 13.399P - 1.748P2 + 6.346K - 0.621K2 + 0.377NP + 0.126NK + 0.090PK and y = 110.352 + 7.636N - 0.311N2 + 7.178P - 0.929P2 + 3.923K - 0.550K2 + 0.152NP + 0.175NK + 0.173PK, respectively. Per kg nutrient increased rape yield by N 5.36 kg，P2O5 7.78 kg，K2O 4.14 kg; N + P2O5 3.74 kg，N + K2O 2.83 kg，P2O5 + K2O 2.18 kg，N + P2O5 + K2O 3.85 kg, respectively.