The purpose of this study is to demonstrate the superiority of efficacy of DWP14012, once daily (QD), compared to placebo in patients with non-erosive reflux disease at Week 4.

This is a multi-center, double blind, randomized, placebo-controlled, parallel-group, phase 3 study. Subjects will be randomly assigned to one of the three treatment groups (DWP14012 A mg or DWP14012 B mg or placebo).

Inclusion Criteria:

1. Subjects aged between 20 and 75 years
2. Subjects who were not observed mucosal break according to the LA classification(LA grade) on the EGD
3. Subjects who had experienced major symptom within 3 months
4. Subjects who had experienced major symptom within 7 days before randomization. Entry into study also required that patients had experienced at least mild symptoms on at least 2 days/week or at least moderate symptoms on at least 1 day/week
5. Subjects who is able to understand and follow the instructions
6. Subjects who voluntarily signed written informed consent form

Exclusion Criteria:

1. Subjects who have Barrett's esophagus, gastroesophageal varices, esophageal stenosis, ulcer stenosis, active gastric ulcer, gastrointestinal bleeding or malignant tumor confirmed by endoscopy
2. Subjects who have erosive esophagitis, acute upper gastrointestinal bleeding, gastric ulcers or duodenal ulcers within 2 months before Visit 1
3. Subjects diagnosed with functional dyspepsia, primary esophageal motility disorder, IBS, IBD in the last 3 months
4. Subjects who have a history of gastric acid suppression surgery or gastroesophageal surgery
5. Subjects with Zollinger-Ellison syndrome
6. Subjects with eosinophilic esophagitis
7. Subjects with clinically significant liver, kidney, nervous system, respiratory, endocrine, hematologic, cardiovascular, urinary system disease .