Abstract: ObjectiveTo retrospectively analyze the efficacy，safety and progrostic factors affecting responses of imatinib mesylate as the first-line therapy for Chinese patients with recurrent or metastatic gastrointestinal stromal tumors（GISTs）. Methods Patients treated with imatinib mesylate 400mg daily as the first-line treatment from Apr. 2003 to Mar. 2012 were followed up. Short-term efficacy was evaluated according to RECIST version 1.0 criteria and toxicity according to NCI CTC version 3.0 criteria. Relative factors affecting time to progress（TTP）and overall survival（OS）were stratified analyzed using SPSS 13.0 software. Results Totally there were 105 cases enrolled in this retrospective analysis，with median followingup duration of 126 months（range：44-348months），meanwhile 36 patients died during the period. The response rate was 66.6％ and disease control rate was 79.9％，including 8（7.6％）cases of CR，62（59.0％）of PR, 14（13.3％）of SD and 21 cases（20.0%）of PD. Median TTP and OS of all cases were 61.5months and 60.0 months（95％CI：52.1-67.8 months），respectively. After being stratified，cases were enlisted into three comparative groups：adjuvant or not groups，second-line or not groups and treatment discontinued or not groups. TTP and OS of patients in adjuvant or second-line groups had no significant differences compared with “not” groups. Contrarily，TTP and OS of patients with treatment discontinued for 3-12months was significantly decreased compared with discontinued less than 3 months（P＜0.05）or continued group（P＜0.05），while no difference observed between latter two groups. Common toxicities were fatigue, skin mucosal edema, leukopenia, diarrhea, etc. mainly in grade 1-2，with no treatment-related death. Conclusion Imatinib mesylate 400mg daily as the first-line therapy for patients with recurrent or metastatic GISTs was safety and effective. Considering the compliances and economy of Chinese GISTs'patients，receiving adjuvant or second-line therapies or not probably have minor influences on TTP and OS. Impressively，treatment discontinued longer than 3 months maybe induce disease progression and translate into disadvantage of OS finally.