The present invention relates to a novel compound or a salt thereof, which is useful as a CRTH2 antagonist, especially as a medicament for disorder that participates eosinophil, for example, allergic disorder such as asthma, allergic rhinitis, allergic dermatitis, conjunctival inflammation, hives, eosinophilic bronchitis, food allergy, inflammation of the nasal sinuses, multiple sclerosis, angiitis, or chronic obstructive pulmonary disease (COPD) and the like.
