The star-shaped poly(l-lactide) (s-PLLA) was synthesized via ring-opening polymerization of l-lactide, with xylitol as a multifunctional initiator and stannous octoate as a catalyst. The structures of s-PLLA were characterized by H-1 NMR spectroscopy, while the molecular weight (M (w)) and polydispersity index were determined by gel permeation chromatography. Bovine serum albumin (BSA) loaded s-PLLA microspheres were fabricated by a water-oil-water (W (1)/O/W (2)) double-emulsion solvent evaporation method. The morphology, drug encapsulation efficiency (EE), and in vitro release behavior of the prepared microspheres were studied in detail. Results indicated that the average diameters of s-PLLA microspheres could be controlled between 7 and 15 A mu m by varying the s-PLLA's concentration or M (w), and the drug encapsulation efficiency of BSA-loaded microspheres were 10-42%. The in vitro study shows that the BSA-loaded microspheres prepared by high molecular weight s-PLLA had a slow cumulative release behavior in phosphate buffer saline (PBS, pH 7.4) and the release process followed the Baker-Lonsdale equation. Present work supposes that the synthesized s-PLLA is a good candidate for drug delivery.