Inclusion Criteria:

- Chronic Myeloid Leukemia in the Chronic Phase

- 20 years old over

- ECOG performance status (PS) score 0-2

- Patients for major molecular response (MMR) with no CMR

- Adequate organ function (hepatic, renal and lung)

- Signed written informed consent

Exclusion Criteria:

- A case with the double cancer of the activity

- Women who are pregnant or breastfeeding

- The case of Pleural effusion clearly

- Patients with complications or a history of severe or uncontrolled cardiovascular
failure following

- have a Myocardial infarction within 6 months

- have an Angina within 3 months

- have a Congestive heart failure within 3 months

- have a suspected congenital QT syndrome

- have a QTc interval of more than 450msec at baseline

- A serious uncontrolled medical disorder that would impair the ability of the subjects
to receive protocol therapy

- Prior treatment with dasatinib

- Subjects with T315I, F317L and V299L BCR-ABL point mutations