Abstract: UV spectra were made for sixty-two bispentadienyl titanium, zirconium andhafnium dihalides. by using 1,2-dichloro cthane as solvent in room . temperature.The absorbancc rules and attributions of the absorption band for these compoundswere presented. The absorption rule of UV spectra, which is presented in thispaper, can be used as a basis for identification of the above three kinds ofcompounds.