Abstract: In order to grope for the coated urea release disciplinarian and for the effect of growth of seedling raising, common urea was taken as CK, three kinds such as L30, L60 and S60 release style polythene-coated urea treatments was laid out, and according to N equality principle, the experiment of cucumber seedling raising has been carried out. The change of N content in substrate, change in polythene-coated urea and in cucumber seedlings were measured on the 15th, 21st, 29th and 36th day, and the healthy index also was measured on last day. The results showed that the Nmin content in substrate and seedlings, and seedling healthy index. are significantly different for different treatment, within that, the N release trend accords with the absorption of cucumber seedling for the treatment of L30. All the plant height, stem thickness, dry weight of single plant are remarkably higher than that of CK, and healthy index increase at 20.2%. Therefore, using L30 polythene-coated urea can realize the target of base fertilizer one times input, and avoid N top dressing, during seedling raising.