Abstract: Ring-opening polymerization of L-lactide was successfully used to prepare single-walled carbon nanotube/poly(L-lactide)(SWCNTs/PLA) composites, and its degradability and thermal stability were explored. Fourier transform infrared (FTIR) spectra, Raman spectra, thermogravimetric (TGA) analysis and scanning electron microscopy were used to characterize the products.The results show that ring-opening polymerization takes place between the functionalized SWCNTs and L-lactide , resulting in attachment of poly(L-lactide) (PLA) chains to SWCNTs, and the SWCNTs/PLA composites can be hydrolyzed under alkaline solution. The DSC study suggests that the presence of functionalized SWCNTs can enhance the glass transition temperature (T_g) of the composite campared with pure PLA.