Abstract: Objective 　To investigate the safety and efficacy of Gastrointestinal St romal Tumors ( GIST) treated with Imatinib mesylate in the Chinise patients. Methods 　52 Chinese GIST patients were diagnosed according to pathology evidence as well as IHC positive CD117 st rain and t reated in Bayi hospital from Aug. 2002 to Dec. 2004. The GIST pts treated with Imatinib mesylate (usage : 400 mg, PO, qd) were carefully observed for efficacy and safety according to WHO and NCI-CTC V2. 0 standards, respectively. Results 　Totally, there are 36 GIST pts treated with Imatinib, 28 pts might be evaluated for the efficacy. There were 14 patient s (50 % ) got PR, 10 pts (35. 7 %) SD over 6 months, only 4 pts (14. 3 %) got PD. That was RR 50 % or DCR 85. 7 %. 36 pts might be evaluated for the toxicity. Except one GIST patient complicated with Non-Hodgkin's lymphoma treated with Imatinib and CHOP regimen chemotherapy showed III grade hypohematocyte, only I～II grade adverse reactions occurred in other 35 pts. Conclusion 　Those result s are consistent with foreigner' s reports. Imatinib is a safe and efficacious molecular target drug used for Chinese GIST. Only mild adverse reactions occur in t reated patient s. It is worth to use Imatinib widely and clinically.