Objective To investigate preoperative blood neutrophil-to-lymphocyte ratio （NLR） in patients with gastrointestinal stromal tumor （GIST） and analyze the relationship of the NLR to prognosis. Methods The data of NLR of peripheral blood samples on 3d before surgery and the results of immunohistochemistry of 42 patients with GIST were analyzed respectively，the relation between the NLR and the prognosis of patients with GIST was understood by the survival analysis. Results The patients with high NLR （NLR≥2.5） was found in 22 cases， low NLR （NLR＜2.5） in 20 cases.The NLR was related to mitotic figures （χ2=9.45，P=0.002） and tumor size （P=0.041）. The 3-year survival rate of the patients with high NLR was shorter than that of the low NLR （χ2=5.44，P=0.022）. The 3-year survival rate was associated with NLR，mitotic figures，and tumor size （P＜0.05） in univariate analysis. The NLR and mitotic figures were independent prognostic indicators of 3-year survival （P=0.018，P=0.000） in Cox multivariate analysis. Conclusion Blood NLR and mitotic figures have some predictive value for the prognosis of patients with GIST.