Cuspidine plays an important role in conventional metallurgical continuous casting mould flux. An UV laser source was used to record its ambient and high temperature Raman spectra (temperature range: 298-1 723 K) combined with a charge coupled device (CCD) detector. Both increasing and decreasing processes as well as characteristic spectra and shifts in wavenumber were observed. Micro-structure of cuspidine in liquid state is not unitary and different from that in solid state, suggesting multi clusters coexisting. Density functional theory (DFT) simulation method was applied to calculate its wavenumbers of Raman active vibrations by introducing the crystal spatial configuration model of cuspidine. Thus the experimental vibrational wavenumbers of the characteristic peaks could be assigned. This will help study physical and chemical behavior of cuspidine in continuous casting mould flux and provide an unique in-situ method under varying temperature with Raman spectroscopic technique.