The fluorescence spectra of three rotational isomers of E-1,2-bis(2-anthryl)ethene (1) were obtained by the principal component analysis-self modeling (PCA-SM) method in solution. Based on the resolved spectra, the orientation of the rotational isomers in nematic and cholesteric liquid crystals (LC) were investigated. 1 mainly exists as the (s-trans, s-trans) conformer in these LC phases.