Abstract: Objective To investigate the efficacy, safety and predictive factors of efficacy of sunitinib in the treatment of patients with imatinib-resistant gastrointestinal stromal tumors. Methods Thirty-two patients with gastrointestinal stromal tumors treated with sunitinib in the Affiliated Hospital of Xuzhou Medical University from March 2012 to October 2017 were recruited. All patients who failured to imatinib were treated with sunitinib 37.5mg daily as second—line to observe and measure its efficacy and reactions. Then they were divided into two groups:group A had treatment-related hypertension while group B did not exist. Results Of the 32 patients,RR was 25% and DCR was 69%, the median PFS was 43 weeks while the median OS was 78 weeks. The median PFS in group A and group B were 74 weeks and 26 weeks respectively. The median OS was 114 Week and 69 weeks. Patients in group A had a longer PFS and OS compared with those in group B.The difference between the two groups was statistically significant (P <0.05). Conclusion The second-line sunitinib treatment is safe and effective in patients with GIST. Sunitinib-induced arterial hypertension may also serve as biomarker of antitumor efficacy.