Abstract: Objective:To evaluate the response rate and survival benefit of imatinib mesylate for advanced gastrointestinal stromal tu -mors (GIST).Methods:Sixty-one patients with unresectable GIST were recruited and given imatinib mesylate with an initial oral dose of 400 mg/day and received regular follow- ups to evaluate the response rate, survival benefit, and adverse effects. Results: The re -sponse rate was 57. 4% (35/61), and the disease control rate was 88. 5% (54/61) one year after initial treatment. Analysis of the Logic regression model shows that gender, age, and multiple lesions in the abdominal and pelvic cavity are factors that affect response rate (P<0. 05). The five-year cumulative survival rate is 53%. The status of multiple lesions in abdominal and pelvic cavity affected the surviv-al benefit of the cases ( P<0. 05). Although adverse effects frequently occur, most of them were mild except for two hemorrhagic cases. Conclusion: The clinical use of imatinib mesylate significantly increases the survival of patients with unresectable or metastatic GIST. The efficacy and safety of imatinib mesylate guarantees it as a treatment choice for advanced GIST.