To Evaluate the efficacy of Z-338 in subjects with Functional Dyspepsia, focusing on the assessment of subjective symptoms in order to further determine the optimal dosage and efficacy parameters for PhaseIII clinical trials.

Inclusion Criteria:

• Postprandial fullness, upper abdominal bloating and/or early satiety should be at least moderate for 2 days or more at the 7 days at Visit 1
• upper abdominal pain, upper abdominal discomfort, postprandial fullness, upper abdominal bloating, early satiety, nausea, vomit and belching should be at least moderate for at least 2 symptoms for 2 days or more at the 7 days at Visit 1

Exclusion Criteria:

• subjects taht heartburn should be the most bothersome symptom
• Subjects presenting with primary complaints relieved by stool movements (IBS)
• Subjects with diabetes by treatment
• Subjects taht heartburn should be more than moderate