Nylon-11 oligomer was utilized as a matrix to prepare a composite containing nano-sized gold particles. Nylon-11 oligomer was prepared by a thermal degradation of a commercial nylon-11 in vacuum. Weight-average molecular weight of the oligomer was ina range from 500 to 800. Nylon-11 oligomer was formed into a film, and then gold was vapor-deposited onto the oligomer film. The gold-colored oligomer film turned a transparent red after a heat treatment at 120 degrees C. Transmission electron microscopy showed an isolated distribution of nano-sized gold particles in the red film of the oligomer. The gold particles were stable in the oligomer for more than a year, and they were dissolved in CH2Cl2 to produce a stable colloidal solution. These results suggest that the gold particles were not only dispersed in the oligomer film, but they were stabilized by the nylon-11 oligomer to form a composite. IR spectrum of the composite showed that N-H groups of the nylon-11 oligomer were responsible for the interaction between the gold particles and the oligomer. Pulse H-1-NMR measurement suggested that an active molecular motion of the nylon-11 oligomer caused the dispersion of the gold particles.