It is intended to provide a novel receptor of LPA and a method of screening a drug such as an LPA receptor antagonist using the same. Use as a lysophosphatidic acid (LPA) receptor comprising a G protein-coupled protein p2y9. More specifically, use of the G protein-coupled protein p2y9 as a lysophosphatidic acid (LPA) receptor. A method of screening an agonist or an antagonist to the LPA receptor as described above by using the receptor.