Previous studies show that the celery extracts have the allelopathic effect on the Fusarium oxysporium f. sp. Cucumerinum with an inhibitory rate of 12.89%-84.83% and different fresh celery root and root soil extracts have different prohibitive allelopathic strengths against the cucumber wilt. With a steep decline in morbidity, however, the prohibitive allelopathic strengths are within 5.45%-46.95%. An interesting issue is the mechanism of the celery extract allelopathy, including the protective enzyme systems, the soluble substances and the active oxygen metabolism of the cucumber leaf, which were studied by researchers However, little attention was paid to the phenol and nitrogen metabolites in the cucumber leaf To study the mechanisms of the celery root soil extracts allelopathy on the Fusarium oxysporium f. sp. Cucumerinum, the changes in the phenol metabolites and the nitrogen metabolites were analyzed in "Jinchun 4"cucumber leaves treated with the extracts once its first leaf was 5cm wide, including the lignin, the tannin, the chlorogenic acid, the ferulic acid, the amino acid, the soluble protein, the ammonia, the nitrate and the nitrite. It is shown that the phenol metabolites in the cucumber leaves treated with the celery root soil extracts are significantly higher those without the treatment, the content of the nitrogen metabolites changes significantly, the contents of the Arg, the Pro, the soluble protein, and the ammonia are higher, but the contents of the Gly, the Val, the Met, the Ile, the Phe and the nitrate are lower. For different treatments, the most significant effects on the phenol metabolites and the nitrogen metabolites are caused by the acetone extracts, followed by the ethanol extracts and the distilled water extracts.