The present world-wide leading products are mostly receptor antagonists and agonists and enzyme inhibitors when classified by the mechanism of action. We consider there will be less possibilities of taking the initiative in successful finding of a target for an innovative drug winning a worldwide contest only by taking up known receptors and enzymes. Therefore, we have used the results of current genetic researches to utilize orphan G-protein-coupled receptors (GPERs) whose ligands are not known yet as targets for drug discovery, and have conducted various examinations about how to implement it. The results obtained here can be combined with the conventional methods for drug discovery. Hence, this technology is considered to be the main stream of future drug discovery research.