Sophocarpidin was measured in thin film using a Fourier Transform infrared spectrometer (FTIR) with a vibrational circular dichroism (VCD) module, meanwhile, the theoretical IR and VCD spectroscopy were calculated at the B3LYP/cc-PVTZ and B3LYP/6-311+G(d,p) levels of theory in density functional theory (DFT) within the gas phase. The VCD spectroscopy can exactly obtain the conformational distribution of Sophocarpidin at room temperature and distinctly capture the information of each conformation for the sensitivity to stereoscopic structure of conformation within VCD spectra. It is essential to the drug analysis of sophocarpidin in the future. The conformational contribution at room temperature and structures were determined through the comparison of experimental and simulated spectra. The Boltzmann-weighted IR and VCD spectra based on free energy at the B3LYP/6-311+G(d,p) level of theory show good agreement with the observed experimental spectra. Two main conformations, i.e. A/B-trans C/D-trans and A/B-trans C/D-cis are identified. The ration of two conformations is 60% to 40%. The structure of A/B-ring and C/D-ring are chair-chair and chair-sofa respectively in both two dominant conformation of sophocarpidin.