This experiment was conducted to increase the available constituents contents of Angelica gigas Nakai and to decide the application amounts of nitrogen, phosphorus and potassium fertilizer. The effects of the amounts of their application and absorption on the contents of decursin and sugar in Angelicae gigantis Redix were studied. The decursin contents of root was decreased with increasing the application amount of nitrogen more than 10kg/10a, and increased along with the increasing application level until 20kg/10a and 15kg/10a of phosphorus and potassium, respectively. The decursin yield per 10a was increased with increasing application level until 10kg/10a, 10kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively. The decursin yield per l0a was decreased with increasing application level more than 20kg/10a of nitrogen. The total sugar yield per 10a was increased with increasing the application level until 15kg/10a, 10kg/10a of nitrogen and potassium respectively. But the effect of phosphorus application on the total sugar yield was not observed. The significant negative correlation was obtained between the decursin contents and the nitrogen contents of root$(r=-0.437^{ast})$, and the significant positive correlation between the decursin contents and the contents of phosphorus$(r=0.587^{{ast}{ast}})$ or potassium$(r=0.467^{ast})$ in root. But the significant correlations between the decursin contents and the their contents of shoots were not observed. It is recommended for decursin production to apply 10kg/10a, 15kg/10a and 10kg/10a of nitrogen, phosphorus and potassium, respectively.