To provide a lactic acid-based copolymerized polyester showing excellent resistance to bleeding out, storage stability, satisfactory biodegradability, transparency essential for a packaging material and flexibility sufficient to be molded.

A lactic acid-based copolymerized polyester showing excellent resistance to bleeding out comprise a polyester component (I) comprising a diol component and a dicarboxylic acid component, said polyester containing at least one component selected from a group consisting of a 20 to 45C diol component (A1), a 20 to 45C dicarboxylic acid (B1) and 1,4- cyclohexanedicarboxylic acid component (B2), and a lactic acid component (II), the weight ratio of the polyester component (I) to the lactic acid component (II) being 2/98 to 80/20.