In this study, carbon nanotubes (CNTs) were first modified using N,N'-dicyclohexylcarbodiimide (DCC) dehydrating agents. Subsequently, the poly(butylene succinate)/multiwalled carbon nanotube (PBS/MWNTs) nanocomposites were prepared through facile melt blending. Thermal degradation of these PBS/MWNT nanocomposites was investigated; the kinetic parameters of degradation were calculated using the Coats and Redfern, Ozawa, and Horowitz and Metzger methods, respectively. It was found that the degradation reaction mechanism of PBS and the CNT-C18 containing nanocomposites at lower temperature was likely to produce an F1 model through reaction of random chain cleavage (cis-elimination). However, the reaction mechanism at higher temperature was likely to be a D1 model because of the dominant diffusion control effect. Moreover, it was found that the activation energies of CNT-C18-containing PBS nanocomposites were first increased with the content of CNT-C18, but then decreased after the content was larger than 0.5 wt % for all models at differing heating rates. This may be due to the formation of a conductive network of CNTs in the polymer matrix at higher content of CNTs, which lead to better heat and electrical conductivity. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1231-1239, 2009