The ¹³C NMR chemical shifts have been determined for compounds of the type Cp₂M(OG₆H₄R-P) ₂[Cp=η⁵-C₅H₅; M=Ti, Zr and Hf; R=H, Me, MeO, Cl, Br and I].It was shown that the ¹³C NMR chemical shift of cyclopentadienyl ring moved npfield ae the metal descending down the periodic column.In addition, there is a good linear correlation among the ¹³C NMR chemical shifts of the corresponding carbon atoms in the three aeries of Ti, Zr and Hf compounds containing both phenyl and cyclopentadienyl rings.The correlation coefficient obtained by least-square method is 0.99 or better.