This experiment was conducted to understand the effects of climatic environment on the useful components in Angelicae gigantis radix. The variation of decursin contents in different seven cultivated regions and the relationship between decursin contents and meteorological factors were investigated. The appropriate analytical methods for decursin and decursinol angelate of Angelicae gigantis radix were HPLC method used normal phase column($mu$-Porasil) and GC method. In different cultivated regions, the variation of decursin contents of Angelicae gigantis radix was relatively great, which were high with 4.86%, 4.75% in Bongwha, Yongcheon respectively and was low with 2.33% in Suwon. There was no significant relationship between decursin contents of Angelicae radix and meteorological factors during growing periods, but was negative correlation in average temperature and precipitation, and positive correlation in diurnal change of temperature, radiation and sunshine hours.