Objective To study the expression of interleukin8 (IL-8) protein in villi and decidua of patients with recurrent spontaneous abortion(RSA). Methods The local and quantitative expressions of IL-8 in villi and decidua of 30 RSA patients were shown and measured by immunohistochemistry and Western blotting. Results IL-8 protein immunohistochemical signals were located in the chorioepithelium cytoplasm and decidual cells plasma in RSA group. While in control group the immunohistochemical staining was negative in decidul cells, but positive in glandular epithelium. The quantitative analysis of IL-8 protein by Western blotting, intensity of the immunostaining was higher in RSA group than that in the control group. Conclusion The higher expression of IL-8 in villi and decidua is releated to RSA, IL-8 might take part in the pathologic process of RSA.