The bond polarizability theory was employed in predicting the Raman intensities of CH3CCH, CH3CCD, CD3CCH, CD3CCD and 12CH313C13CH by transferring polarizability parameters from ethane and acetylene. Good agreement between the observed and predicted spectra of CH3CCH was obtained. The effect of isotopic substitution on the intensity of Raman lines is discussed. © 1997 by John Wiley & Sons, Ltd.