The catalytic degradation of prepared matrix poly(butylene succinate) (PBS) and its copolymers by immobilized lipase is carried out in the mixed organic solvent containing a small amount of water. The degradation products were studied with various characterizations techniques, including gel permeation chromatography (GPC), time of flight mass spectrum (TOF-MS), nuclear magnetic resonance (NMR), and Fourier transform-infrared spectroscopy (FT-IR). The results showed that under atmospheric pressure, 60 degrees C, after 24 h catalytic degradation of PBS and its copolymers by immobilized lipase, the yellow oil-like degradation products can be obtained. The lipase has catalytic activity on various copolymers. At the first time, the monomer of BDO was found in the degradation products and the molecular weight of product with aromatic smell is below 1000. The products consisted of cyclic oligomer, linear oligomer and monomers, and cyclic oligomer is at least dimmer. The minimum and maximum degradation yields correspond to PBS (40%) and P(BS-co-CL-co-CHDM) (54%). (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012