To provide a surfactant composition with an excellent foamability and thickening performance and further an excellent storage stability, it comprises the following components (a) and (b): (a) at least one anionic surfactant selected from (1) sulfonate-type anionic surfactants having amide group or ester group, (2) carboxylate-type anionic surfactants and (3) phosphate-type anionic surfactants and (b) a compound expressed by the formula (I): ##STR1##

where R¹CO— is an acyl group having 6 to 24 carbon atoms, R² is an alkyl group having 1 to 3 carbon atoms and R³ is an alkylene group having 1 to 6 carbon atoms or an alkenylene group having 2 to 6 carbon atoms.