The present invention provides: a bicyclic derivative comprising a pyrimidine ring, or a pharmaceutically acceptable salt thereof; a preparation method therefor, a pharmaceutical composition comprising the same; and a use therefor. According to the present invention, the bicyclic compound derivative comprising a pyrimidine ring, or a pharmaceutically acceptable salt thereof acts as a 5-HT4 receptor agonist, and thus can be usefully applied to the prevention or treatment of dysfunction in gastrointestinal motility, for example, gastrointestinal diseases such as gastroesophageal reflux disease (GERD), constipation, irritable bowel syndrome (IBS), dyspepsia, post-operative ileus, delayed gastric emptying, gastroparesis, intestinal pseudo-obstruction, drug-induced delayed transit, diabetic gastric atony and the like.