ANIONIC SURFACTANT COMPOSITION

PROBLEM TO BE SOLVED: To provide an anionic surfactant composition containing a polyoxyalkylenealkyl or an alkenyl ether sulfate ester salt excellent in both foamability and defaomabity in a high concentration, and being excellent in flowability.SOLUTION: The anionic surfactant composition contains (a) a mixture of compounds represented by formula (1): RO-(EO)-(PO)-SOM and (b) water. The average value of m and n in the mixture are each in a predetermined range. The proportion of a compound of 0 in m in the formula (1) and 0 in n therein in the mixture is ≥40 mass%. The total of a compound of ≥2 in m in the formula (1), a compound of ≥2 in n therein, and a compound of ≥2 in m+n therein in the mixture is ≤25 mass%. In the formula (1), R is an 8-12C linear or branched alkyl group or alkenyl group; EO is an ethyleneoxy group; PO is a propyleneoxy group; m and n are each an integer of ≥0; and M is an alkaline metal or NH.