The invention is to provide a method for producing a soft capsule type external preparation (and a softening liquid (L) used for the production thereof, and an external preparation composed of such a capsule body (C)) which can be stably stored and leaves no film residues when rubbed with the finger when used as an external preparation although the external preparation is structured only as a capsule body (C) substantially having no external solution. An original capsule body (c) in which at least the external surface region inside an alginate capsule is present in the form of a polyvalent metal alginate is contacted with a softening liquid (L) composed of an aqueous solution comprising both “a basic amino acid (1)” and “an acid (2) selected from an organic acid or a phytic acid,” thereby impregnating the softening liquid (L) into the original capsule body (c) to obtain the capsule body (C).
