Abstract: Tray caves and substrates of plug seedling affect seedling quality of cauliflower. In order to select a suitable combination of tray cave and substrate for cauliflower nursery, 3 types of seedling substrates named T1, T2, and T3, combined with 50 caves, 72 caves and 128 caves each in a 540mm×280mm seedling tray, were treated to test the index of seedling growth physiology. The results showed that the emergence rate of treatment with 72 caves was significantly higher than that of treatments with 50 caves and 128 caves, respectively. The plant height, stem diameter and seedling rate of treatment with 72 caves were significantly higher than that of treatments with 50 and 128 caves, respectively; the soluble sugar content was significantly higher than that of treatment with128 caves, while the content of soluble protein was not significantly different between treatments. The contents of chlorophyll a and chlorophyll a + b of treatments with 72 caves were significantly lower than that of treatment with 50 caves, but a little higher than that of treatment with 128 caves, respectively; the contents of chlorophyll b and carotene of treatment with 72 caves were significantly higher than that of 128 caves, while no difference compared with 50 caves treatment. The germination rate of T1 substrate(V_{corn stalk}:V_{cattle manure}:V_peat:V_vermiculite:V_perlite=1:2:1:1:1) was significantly higher than any other treatments. After 60 days of seeding, the plant height, stem diameter, seedling rate, chlorophyll b, chlorophyll a + b content, soluble sugar and soluble protein content of cauliflower seedlings with T1 substrate were significantly higher than any other treatments. The contents of chlorophyll a content and carotene with T1 substrate were significantly higher than that with T2 substrate(ChengHe eutrophic substrate for fruits and vegetables, organic matter>45%). Therefore, the tray with 72 caves and T1 substrate was the best combination in this study.