Suppression of nanoparticle aggregation on a plasma membrane surface may lead to better understanding of the causes of various diseases and development of new drug delivery systems. In this study, we inhibited the aggregation of gold nanoparticles on a lipid membrane in a fluidic liquid-crystalline phase by using nanosized liposomes to increase steric hindrance. Adsorption of liposomes on gold nanoparticles was confirmed by transmission electron microscopy and ultraviolet-visible absorption spectroscopy. The ability of the liposomes to suppress gold nanoparticle aggregation strongly depended on the concentration of liposomes providing steric hindrance. The fluidity or rigidity of the liposome membrane also strongly influenced the ability of the liposomes to suppress gold nanoparticle aggregation.