Compare MMR on 12 month treated with half TKIs(including imatinib, dasatinib, and nilotinib) or TKIs withdrawal.

1. Chronic myeloid leukemia-Chronic phase(CML-CP) patients treated with receive effective Tyrosine kinase inhibitor -TKI(including imatinib, dasatinib and nilotinib) for more than 5 years, and patients with BCR/ABLIS continuous negative in the last 18 months were randomly admitted to maintain the original effective TKI by half or stop taking .
2. Q-pcr detected BCR/ABLIS in peripheral blood once every month, once every two months after half a year, and continuously monitored for 12 months.
3. If the patients detected molecular recurrence (loss of MMR, BCR/ABLIS > 0.1%), the original dose of TKI should be administered again.

Inclusion Criteria:

1. Age 18-70 years old, gender is not limited;
2. Diagnosed CML chronic phase and effective TKI(including imatinib, dasatinib, and nilotinib) was continued for more than 5 years
3. Q-PCR monitored BCR/ABLIS duration < 0.0032% in the last 18 months
4. Informed consent of the patient or his legal representative

Exclusion Criteria:

1. Patients had history of CML-AP or CML-BC
2. CML patients with previous or current ABL kinase mutations
3. CML Patients who have received allogeneic hematopoietic stem cell transplantation
4. CML Patients who have received immunotherapy (except interferon, including car-t and other cellular immunotherapy)
5. Woman who is pregnant or nursing

Diagnosed CML chronic phase,Age 18-70 years old,gender is not limited