Compounds represented by formula (I) ##STR00001## wherein all symbols represent the same meanings as described in specification. and salts thereof.Since the compound represented by the formula (I) binds and antagonizes to DP receptor, it is useful for the prevention or treatment against the disease such as allergic disorder, diseases accompanied with itching, secondary diseases generated by behaviors caused by itching, inflammation, chronic obstructive pulmonary disease, ischemic reperfusion disorder, pleuritis complicated by rheumatoid arthritis, cerebrovascular disease, and ulcerative colitis.