A series of ABA triblock copolymers of poly (L-lactic acid) and poly(tetramethylene ether) (PLLA-b-PTME-b-PLLA) have been synthesized and thoroughly characterized. The enzymatic degradation of the PLLA segment in the copolymer was investigated based on electrospun fiber membranes. Through the manipulation of PTMEG content in the triblock copolymer, the hydrolysis rate of PLLA segment by enzyme can be well controlled. The enzymatic degradation of PLLA segment in the electrospun fiber membranes decreases with increasing PTMEG content in the copolymer, while the weight loss percentage of the PLLA segment increases exponentially with time, indicating that the enzymatic degradation of PLLA segment is a diffusion-controlled process. As found, within the scope of our experimental range, the diameter of the electrospun fiber has no significant effects on the hydrolysis rate of PLLA segment in the copolymer. (C) 2012 Elsevier B.V. All rights reserved.