A simple method to fabricate polymer nanocomposites with single-walled carbon nanotubes is reported, in which the nanotubes were reacted with poly(L-lysine) by using high-speed vibration milling. The nanocomposites obtained were characterized by Fourier transform infrared (FT-IR), UV-Vis spectroscopy, and thermogravimetric methods. The morphology as well as the dispersion of the carbon nanotubes were determined by scanning and transmission electron microscopy.