Abstract：In this research，3 types of trays：128，200 and 288 apertures and 3 seeding density：1，2 and 3 grains are used to study the effects of different single plant rooting-zone volume on growth potential，photosynthetic capacity，economic output and nitrate nitrogen content of pakchoi〔Brassica campestirs ssp.?chinensis（Ｌ.）Makino var.?communis Tsen et Lee〕．The result shows that the growth differences of pakchoi seedlings under different single plant rooting-zone volume are significant．When the single plant rooting-zone volume is 13.0 mL，the per plant quality is better and the economic output is higher．At single plant rooting-zone volume 13.0 mL，we compared the differences between varieties and the result shows that there are remarkable differences between varieties，and the tested variety‘Zhonghuawang’is the best one.
