PURPOSE: To produce the subject compd. being a surfactant while preventing side reaction by using a selective hindered base while minimizing the use amt. of anhydrous chloroacetic acid or a salt thereof to convert ethoxylated alcohol.

CONSTITUTION: A compd. represented by formula I (wherein R is 8-18C alkyl; and x is 1-15 on an average) is reacted with anhydrous chloroacetic acid or its alkali (alkaline earth) metal salt (a molar ratio of hindered base; anhydrous chloroacetic acid; 2:1 and, in the case of the salt, 1:1) in the presence of a hindered base represented by formula II [wherein RO- is secondary or tertiary alkoxide; R is alkyl; and M is alkali (alkaline earth) metal cation] to obtain an alkylethoxycarboxylate surfactant represented by formula III. By this method, the use amt. of anhydrous chloroacetic acid can be minimized. Further, side reaction is prevented and it is unnecessary to remove an undesirable contaminant.