Abstract: Star-shaped poly(ε-caprolactone)(SPCL) was synthesized by ring-opening polymerization of ε-CL from hydroxyl end-capped cyclophosphazene initiators. The SPCL was used as flame-retardant plasticizers for polylactide(PLA) and compared with liner poly(ε-caprolactone)(LPCL) and acetyltributyl citrate(ATBC). The experiment data the plasticization efficiency of SPCL was higher than that of LPCL, but lower than that of ATBC. When 20 phr SPCL was added, the ultimate elongation of the PLA/SPCL composites increased from 7.40% to 18.86%. Meanwhile the tensile strength of the PLA/SPCL composites was obviously superior to the other composites. Thermo-gravimetric analysis (TGA) and limited oxygen index (LOI) results indicated that the addition of SPCL can promote the flame retardancy of the composites and had tiny effect on crystallinity and thermal stability of PLA. Migration tests showed that there no migration was determined for PLA/SPCL composites. Compared with ATBC SPCL, SPCL was an excellent nonmigrating plasticizer.