Provided is a novel aromatic ring compound which may have a GPR40 agonist activity and a GLP-1 secretagogue action. A compound represented by the formula (I): wherein each symbol is as described in the DESCRIPTION, or a salt thereof may have a GPR40 agonist activity and a GLP-1 secretagogue action, may be useful for the prophylaxis or treatment of cancer, obesity, diabetes, hypertension, hyperlipidemia, cardiac failure, diabetic complications, metabolic syndrome, sarcopenia and the like, and may afford superior efficacy.本發明提供一種可具有GPR40促效劑活性與GLP-1促分泌作用之新穎芳香環化合物。如式(I)代表之化合物: 其中各代號係如說明書中說明,或其鹽,可具有GPR40促效劑活性與GLP-1促分泌作用,可用於預防或治療癌症、肥胖症、糖尿病、高血壓、高血脂、心臟衰竭、糖尿病併發症、代謝症候群、肌少症等等,且可提供優異藥效。