A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends. A series of neutral bimetallic lanthanide aryloxides p-C6H4 [OLnL (THF) n] 2 [Ln = Y1, Yb2, Sm3 and n4 , L = Me2NCH2CH2N {CH2- (2-0- C6H2- tBu2-3,5)} 2] and alkoxides p-C6H4CH2 [OLnL (THF)] 2 [Ln = Y (5), Yb An amine-bridged bis (phenolate) ligand has been synthesized through one-pot reactions of Ln (C5H5) 3 (THF), LH2 with p-benzenediol and 1,4- benzenedimethanol, respectively. All complexes have been characterized satisfactorily by elemental analyzes , single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy (in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of The influence of lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of BBL, except for 3 and 4 in the case of BBL. of polymerization were systematical ly studied and compared. Highly heterotactic PLA (Pr up to 0.99) and syndiotactic PHB (Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.