Abstract: As the first line of therapy for chronic myeloid leukemia, the outcome of imatinib is encouraging. The plasma concentration of imatinib is correlated with remission rate and survival, and affected by α1 acid glycoprotein(AGP) and those drugs which will change the activities of cytochrome P450(CYP3A4). It is conductive for the treatment of CML by monitoring the plasma concentration of imatinib.