Abstract: Imatinib and the second generation tyrosine kinase inhibitors(TKI) not only have revolutionized the management of patients with CML,but also become a model for the development of novel targeting agents in treating malignancies. Under IM treatment.more than 90%CML-CP patients could achieve complete hematologic remission,and more than 80% patients could achieve CCyR/MMoR.,the event free survival at 6-7 years were around 80%.resulting in a major change in the natural history of CML.Nevetherless, TKI cannot eliminate the bcr-abl fusion gene or CML stem cells.the patients have to take the medicine continuously or for life long,More than 10%patients developing resistance Or intolerance are also problematic.The available TKI are preferable choice for treatment of CML