Abstract: In this paper, we discuss the dynamics of soluble sugars, gibberellins, tannins and flavonoids during the life cycle of Iva xanthifolia, to enrich our understanding of this asteraceae weed that is widespread in northeast China. Most studied metabolites peaked in seeds or sprouts, although their contents differed. In addition, different soluble sugars had similar tendencies at different stages: sprout> inflorescence> seedling> adult> seed. Except for in inflorescences and seedlings, trehalose had a movement of sprout> adult> seed. We determined raffinose in the seed at 15.4329 mg. g-1. Giberellins had an obvious change in pattern, as seed> sprout≈seedling≈inflorescence> adult. Tannins and flavonoids each had a trend of seed> adult> seedling> sprout> inflorescence and seed>sprout> adult≈inflorescence> seedling, respectively. Remarkably, when the ratio of tannins to flavonoids neared 1, the plant had a low concentration of tannins and flavonoids; in contrast, when the value neared 0, the plant had a high level of tannins and flavonoids.