Biodegradable poly(ethylene succinate)(PES)/carboxyl-functionalized multi-walled carbon nanotubes (f-MWNTs) nanocomposites were prepared through solution casting method. Scanning electron microscopy observations show a homogeneous dispersion of f-MWNTs throughout the PES matrix. Effect of f-MWNTs on the crystallization behavior of PES was investigated in detail under different crystallization conditions in this work. For both nonisothermal and isothermal melt crystallization, the addition of f-MWNTs enhances the crystallization of PES apparently due to the heterogeneous nucleation effect. The Ozawa method does a good of describing the nonisothermal melt crystallization of neat PES and its nanocomposites. The Avrami method does a good of describing the isothermal melt crystallization kinetics of neat PES and its nanocomposites; moreover, the overall crystallization rate of PES is enhanced significantly while the crystallization mechanism remains unchanged in the presence of f-MWNTs in the nanocomposites. The crystal structure of PES remains unchanged in the PES/f-MWNTs nanocomposites despite the presence of f-MWNTs. (C) 2011 Elsevier B.V. All rights reserved.