The objective was to use STI571, a kind of tyrosine kinase inhibitor, to treat acute myeloid leukemia (AML) with Philadelphia chromosome. 2 AML cases with Philadelphia chromosome, were collected to observe effect of STI571. One of them was given STI571 after routine chemotherapy failed to respond to treatment, other case received routine chemotherapy only. Both of them underwent HLA-matched/mismatched sibling hematopoietic stem cell transplantation (HSCT). The results showed that cytogenetic and hematologic CR was acquired in case 1 with STI571 while another one gained hematologic CR by accepting routine chemotherapy. Recovery of hemopoiesis was found at 18 and 11 days after HSCT respectively without serious graft-versus-host-disease. The case 1 has been surviving in disease-free state for 5 months since HSCT. The case 2 died from interstitial pneumonia at 8 months after HSCT. In conclusion, STI571 is one of choice for the treatment of Philadelphia chromosome positive AML.