To obtain the subject compound useful for the production of a synthetic detergent, containing an active substance in a high content, and having a good flowing property even at a relatively low temperature and a storage stability against a hydrolysis and a phase separation.

This objective flowable anhydrous acyloxyalkanesulfonate is obtained by reacting a fatty acid represented by the formula: RCO-OH (R is a 5-31C hydrocarbon) with at least one hydroxyalkanesulfonate represented by the formula: HO-R1-SO3X [R1 is a (C3-C4)-alkylene or the like, X is an alkali metal or ammonium] in (1:1)-(2:1) molar ratio in the presence of an esterification catalyst such as sulfuric acid at preferably 190-230°C temperature, while removing present water for performing an esterification, cooling the product preferably at 60-110°C temperature, and then sharing the product so as to have 10-80 μm mean particle size. The compound further shows a good water solubility and stability to a hard water, a high foaming property and a good action to skin.