This study is designed to evaluate the efficacy and tolerability of ilaprazole relative to that of esomeprazole in healing erosive esophagitis and resolving accompanying symptoms of GERD.

Inclusion Criteria:

• Consenting patients will be eligible for enrollment if they:
• are 18-70 years of age,
• have at least one of the two symptoms, heartburn and reflux,
• have photographically documented erosive esophagitis confirmed by esophagogastroduodenoscopy(EGD), and graded according to the Los Angeles (LA) Classification (A-D), within 5 days before randomization to treatment. Female patients are required to be nonpregnant, nonlactating, postmenopausal, surgically sterilized, or using a medically acceptable form of birth control, as determined by the investigator. Women of child- bearing potential will receive a pregnancy test.

Exclusion Criteria:

• Patients will be ineligible if they:
• have cancerous or peptic ulcers, Zollinger-Ellison syndrome, varices of esophagus or fundus of stomach
• have a known history of gastric acid suppression operation, esophageal operation or peptic operation other than simple closure of perforation,
• have severe complications, severe other diseases of digestive tract such as Crohn's disease and ulcerative colitis, and severe other systemic diseases,
• have taken proton pump inhibitors within the 5 days or for more than three consecutive days within the two weeks immediately preceding start of study drug,
• participated in a clinical trial with an investigational drug or device within the past three months,
• have hypersensitivity or idiosyncratic reaction to ilaprazole, esomeprazole or any other benzimidazole,
• have alcoholic intemperance, drug addiction or any other improper habits.