The major components of the 4th generation outer space bred angelica and the ground group were determined and analyzed by Fourier transform infrared spectroscopy (FTIR) and second derivative spectrum, considering the large mutation of the plants with space mutagenesis. The results show that the content of the coumarin ( 1741 cm-1), which is the main active components of the space angelica dahurica increased, and the content of the protein (1 459, 1 419 cm-1) and the fat (930 cm-1) increased slightly, whereas the content of the starch and the dietary fiber reduced drastically. There are obvious differences between the peak values of the second derivative spectra of the plants, revealing that the outer space angelica dahurica contained amine component at 1 279 cm-1. Space mutation breeding is favor of breeding angelica with better idiosyncrasy.