SURFACTANT COMPOSITION

PROBLEM TO BE SOLVED: To provide a liquid surfactant composition that contains a polyoxyalkylene alkyl ether sulfate ester salt with a predetermined branching fraction in high concentration and is excellent in stability. SOLUTION: The surfactant composition contains (a) 40-58 mass% mixture of a compound represented by general formula (1): RO-(PO)m(EO)nSO3M, in the mixture the ratio of a compound, of which R in general formula (1) is a hydrocarbon group having a branched chain, is 0 mass% or higher and not higher than 50 mass%, (b) 13-20 mass% at least one of a 1-6C lower alcohol, and (c) 22-47 mass% water. In general formula (1), R is a 8-24C hydrocarbon group; PO and EO are a propyleneoxy group and an ethyleneoxy group, respectively; m and n show the addition numbers of moles of PO and EO, respectively, and are such numbers that their mean values in the mixture of the compounds represented by general formula (1) are 0