Abstract: The effects of planting density (D) and fertilization ratio of nitrogen (N), phosphorus (P) and potassium (K) on yield of seedling-use Chinese cabbage were investigated by a field experiment, quadratic orthogonal regressive rotation design with four factors was used. A regression model of planting density and fertilization amount on seedling-use Chinese cabbage yield was established, single and coupling effects were analyzed. The results showed that if other factors were in medium level, the seedling-use Chinese cabbage yield first increased then decreased with the increase of planting density and NPK application rate. The order of each factor on yield was N (X2) ＞D(X1) ＞ P (X3) ＞ K (X4). There were positive interactions between planting density and N application rate, and between planting density and P application rate, and the interaction of planting density and N application was greater than that of planting density and P application. It was concluded that too high or too low of planting density or N, P and K application rate did not benefit the yield increase of seedling-use Chinese cabbage, and medium planting density and NPK fertilization could enhance the yield of seedling-use Chinese cabbage.