A new compound, 3-(1H-tetrazol-5-yl)oxanilic acid and pharmaceutically acceptable salts thereof are herein disclosed, which can be prepared by reacting 3-(1H-tetrazol-5-yl)aniline with a compound represented by the general formula: A--CO--CO--B (wherein A and B may be identical with or different from one another and represent hydroxyl group, a halogen atom or a lower alkoxy group) and then optionally hydrolyzing the resultant product. The compound presents an excellent histamine and SRS-A release inhibitory effect and is hydrophilic or soluble in water. Therefore, the compound is very suitable to form, in particular, an aqueous pharmaceuticals for treatment or prevention of allergic diseases such as bronchial asthma, rhinitis and conjunctivitis.