Fabrication process was successfully used to embed carbon nanotubes (CNTs) in a polylactic acid (PLA) matrix, forming a composite nanostructure. For the composites, nanoindentation is often used to characterize their mechanical properties (e.g., hardness and Young's moduli). In this experiment, the varied concentrations of CNTs in PLA were analyzed in their mechanical performance. The distribution and conformation of CNTs in the PLA were studied by X-ray diffraction. Then, electrical characterization was performed by four-probe method.Thermal properties were checked by TGA and DSC. Furthermore, the CNTs/PLA nanocomposites were observed by SEM. According to the experimental result, purified CNTs showed better dispersing and properties in the CNTs PLA nanocomposites.