A series of star-block Poly(L-lactide)-b-poly(ethylene oxide) (SPLLA-b-PEO) copolymers were synthesized by ring-opening polymerization (ROP) and DCC chemistry. The inclusion complexes of SPLLA-b-PEO copolymers and g-cyclodextrin (alpha-CD) were prepared with two different methods. FTIR, H-1 NMR, WAXD, DSC, and TGA indicate that alpha-CD only can be threaded onto PEO blocks in inclusion complexes of alpha-CD-SPLLA-b-PEO1.1K-a, alpha-CD-SPLLA-b-PEO2K-a, and alpha-CD-SPLLA-b-PEO5Ka formed without heating and ultrasonication, and can be threaded onto both PLLA and PEO blocks in inclusion complexes of,alpha-CD-SPLLA-b-PEO1.IK-b, alpha-CD-SPLLA-b-PEO2K-b, and alpha-CD-SPLLA-b-PEO5K-b formed with beating and ultrasonication. Namely, alpha-CDs can be threaded onto PEO blocks and the flanking bulky PLLA blocks of star-block copolymers to form stable polyseudorotaxanes with heating method and ultrasonication to conquer the activation energy barrier of the inclusion complexation between bulky PLLA and alpha-CD and the effect of the steric hindrance of star-block copolymers. With the alteration of preparing methods, the inclusion complexes of a-CD with the outer PEO block or PEO and PLLA blocks were obtained successfully. (c) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2754-2762, 2009