A series of copolymers of lactide (LA) and e-caprolactone (e-CL) with different monomer feed ratios were achieved using three kinds of bimetallic Schiff aluminum complexes as catalysts. The ratios of LA and e-CL units in different copolymers and the average segments length were determined by NMR analysis. The comparative kinetic study of L-LA/e-CL and rac-LA/e-CL copolymerization systems showed that the polymerization rate of LA was faster than e-CL, and L-LA showed polymerization rate slightly faster than rac-LA. It was inferred that the copolymers achieved by these complexes were gradient copolymers with gradual change in distribution of LA and e-CL units. The thermal properties of these copolymers were characterized by DSC analysis, which showed that the glass transition temperature (Tg) of these copolymers changed regularly according to the pro-portion change of two structural units.