Abstract: Erigeron breviscapus a medicinal plant was planted under different nitrogen levels to investigate effects of nitrogen on the growth and the accumulation of secondary metabolites, address the relationship between them in medicinal plants in the plantation. Results showed that the amount of N fertilizer was significantly positively correlated with the biomass, but negatively to contents of total caffeates and scutellarin of Ebreviscapus Moreover, increasing amount of N fertilizer did not significantly enhance yields of 2 active constituents. The biomass was negatively correlated with contents of total caffeates and scutellarin. Contents of total caffeates and scutellarin were negatively correlated with contents of N in Ebreviscapus, as predicated by the carbon/nutrient balance hypothesis. The result suggested that the nitrogen addition could increase the biomass yield, nevertheless, decrease active constituents ( flavonoids )，there could be a trade off between the growth and accumulation of secondary metabolites in medicinal plants.

Key words: Erigeron breviscapus