Amphiphilic small molecules comprising a cholesterol moiety and an AB(2)-type aryl ether dendron bearing oligo (ethylene glycol) chains at the outer periphery were synthesized. The amphiphilic cholesterol derivatives exhibited lower critical solution temperature behavior with excellent thermo-sensitivity in aqueous solutions. During the separation of organic dyes from aqueous solution by cloud point extraction (CPE) utilizing the cholesterol derivatives, the CPE efficiencies of the organic dyes were well correlated with their clog P values.