In order to reform the traditional heavy seedling technique Brassica oleracea var. italica, it revealed the growth rules of plug seedlings in Brassica oleracea var. italica, promoting industrialization and improve quality plug seedlings in Brassica oleracea var. italica, and applying with hole tray of different specifications and matrix, with such impact application, the experimental results showed the seed germination rate increased and the order at any time a curve change rule, the mathematical model was that y=25.431+20.783d-1.3811d 2 (r=0.9919**, r0.01=0.7348); seedlings at any time sequence, the high growth and a slow-fast-slow change rule, the mathematical model was that h=-0.0008d2+0.3856d-0.7077 (r=0.9882**, r0.01=0.7348); seedlings stem diameter was always the sequence to increase and the growth in the first slow, quick growth rule, the mathematical model was that S=0.0332d+0.6471 (r=0.9877**, r0.01=0.7348). The main influence factors on seedling growth over a matrix, basal and climate, using the growth rule and model or adjusting determined comprehensively seedling technique measures had the important instruction meaning.