Alpha-sulfofatty acid ester salt-containing solution

An alpha-sulfofatty acid ester salt-containing solution that contains an alpha-sulfofatty acid ester salt (a) having 16-18 carbon atoms in the fatty acid residue, a fatty acid polyoxyalkylene alkyl ether (b) and water, characterized in that: the total content of (a) and (b) is more than 30 mass% and not more than 40 mass% relative to the total liquid; and the ratio by mass [(a)/(b)] is 1.5-9.0 inclusive. When allowed to stand, this alpha-sulfofatty acid ester salt-containing solution maintains high homogeneity of the liquid and scarcely causes separation or precipitation. 种含α-磺基脂肪酸酯盐的液体，其特征在于，含有脂肪酸残基的碳原子数为16～18的α-磺基脂肪酸酯盐(a)、脂肪酸聚氧化烯烷基醚(b)和水；相对于全部，(a)和(b)的总含量大于30质量％、在40质量％以下；(a)/(b)之质量比在1.5以上、9.0以下。该含α-磺基脂肪酸酯盐的液体即使静置保存，液体的均性也得以保持良好，难以产生分离、析出。