Field experiment with 6 level N rates was conducted in 1998 to study the effects of N rates on yield, nitrate content of Chinese cabbage and N apparent losses. The results showed that, the optimum economic N rate was 310 kg hm^-2 (N), the nitrate content of plant and the N apparent losses in soil plant system increased with increasing N rate. It was not possible to coordinate the yield effect, crop quality effect and environmental effect under experimental condition. Reducing vegetable nitrate content by other strategies, improving current planting system and studying environmental economics of fertilization, are the main problems to be solved in the future.