This study was purposed to evaluate the efficacy and safety of nilotinib for treating patients with imatinib-resistant or intolerant chronic myeloid leukemia (CML). A total of 23 patients with imatinib-resistant or intolerant CML were enrolled in this study. These patients received nilotinib orally 600-800 mg every day, their curative efficacy, tolerance and overal survival were evaluated. The results showed that all the patients treated with nilotinib obtained complete hematologic remission (CHR), out of them 82.6% patients achieved complete cytogenetic remission (CCyR) and 56.5% patients achieved complete molecular remission (CMR), their adverse events mostly were mild to moderate, generally were transient and easily cured; the median treatment time with nilotinib was 13.5 (1-44) months, and the median follow-up time was 40 (12-102) months. It is concluded that nilotinib has been confirmed to be effective for patients with imatinib-resistant or intolerant CML, and may be selected as a second generation of tyrosine kinase inhibitor (TKI).