Triacetin (TAC) is known as a lubricant of poly(L-lactide) (PLLA), and it is used to improve the mechanical properties of PLLA. However, the compatibility of TAC with PLLA and the morphological changes induced by the addition of TAC to PLLA have not been clarified. This study investigates the effects of the addition of TAC on the morphological changes and physical properties of PLLA. We prepared the PLLA films containing a given amount of TAC by solvent-cast blending with chloroform under a low temperature. From the investigation of the mechanical properties of the blends, it is found that the glass-transition temperature of PLLA is remarkably decreased with an increasing amount of TAC, the blend films exhibit high elastic recovery, and the degree of the recovery increases linearly with the amount of TAC. The morphological changes exhibiting high elastic recovery are discussed. (C) 2003 Wiley Periodicals, Inc.