The theoretical investigation of the chiral optics is induive to the elucidation of the optically rotational mechanism and the design of the novel chiral drugs. The optical rotation (OR), the vibrational circular dichroism (VCD),and the electronic circular dichroism (ECD) spectra of a series of newly-found bio-active molecules, bruguierols A—C, are calculated with the gradient-corrected density functional theory method. On the basis of molecular structure, normally vibrational modes and electronic structure, we explore the microscopic origin of molecular chirality and discuss the solvent effects of OR and ECD spectra. The results show that the introduction of OH modulates the molecular chirality. The methyl group and the phenyl group enhance the molecular chirality. The normal vibrations and the electronic transitions on the chiral skeleton play critical roles in producing the chiral spectra. The solvent effect decreases OR and weakens the ECD spectra.