PURPOSE: To obtain the titled solution, by neutralizing and hydrolyzing a reaction product of sulfonation of an olefin in the presence of a specific amount of a specified polyethylene glycol or polyoxyethylene alkyl ether and an aromatic carboxylate.

CONSTITUTION: A reaction product of sulfonation of 10W20C olefin is neutralized and hydrolyzed in the presence of 1W10pts.wt. total amount of 0.5W7pts.wt. at least one selected from a polyethylene glycol having about 200W6,000 molecular weithgt and a polyoxyethylene alkyl ether having 8W18C alkyl group and 5W30 average number of addition moles of ethylene oxide based on 100pts.wt. olefinic sulfonate in a solution of the final reaction product and the same ratio of an aromatic carboxylate shown by the formula (R1 is OH, etc., ; M is H, alkali metal, etc.), to give the desired solution containing ≥60wt% olefinic sulfonate.