A gelling agent for an oil, which contains at least one compound (A) and at least one compound (B), and a gel composition containing the gelling agent and an oil: ##STR00001## wherein R.sub.1 is a straight chain or branched chain, saturated or unsaturated hydrocarbon group having 7 to 17 carbon atoms, R.sub.2 is a straight chain or branched chain, saturated or unsaturated hydrocarbon group having 1 to 26 carbon atoms, R.sub.3 and R.sub.4 are each independently a straight chain or branched chain, saturated or unsaturated hydrocarbon group having 1 to 26 carbon atoms, and R.sub.5 is a straight chain or branched chain, saturated or unsaturated hydrocarbon group having 7 to 17 carbon atoms.