The Raman spectra of coke (1 300 - 1 650 cm-1) are measured by a multi-channel laser Raman spectrometer. The spectra are analyzed by Lorentzian fitting continuously and the intensity ratio of peaks (R-value, I.1 360 cm-1 / I.1580 cm-1) is calculated automatically. The histogram of R-values is drawn up. The advantage of this method compared with the powder X-ray diffraction method which has been used until now is that sample preparation, for example, crushing, de-ashing and forming, is not needed. The measuring time (3 min) is shorter than that of the previous method (30 - 40 min).