Objective To explore the expression of chemokine(C- X- C motif) ligand(CXCL)5 in patients with gastric cancer and analysize the roles of CXCL5 in the development,invasion and metastasis of gastric cancer. Methods The tissue specimens of 260 patients surgically treated in the Department of General Surgery, Affiliated Tumor Hospital of Zhengzhou University were collected, and 60 serum samples were collected.The expression of CXCL5 protein in tumor tissues and case- paired normal tissue samples was detected by immunohistochemistry(IHC).The concentration of serum CXCL5 in 60 cases of gastric cancer and 25 healthy volunteers was measured by enzyme linked immunosorbent assay(ELISA). Results The IHC revealed that the positive expression rate of CXCL5 was significantly higher in tumor tissues[37.69%(86/260)] than in corresponding normal tissues[6.53%(17/260), P< 0.01]. The expression of CXCL5 was correlated with tumor size (P< 0.05), pathological types(P< 0.05), intravascular cancer emboli(P< 0.05), T staging (P< 0.05)and N staging(P< 0.05).The expression of CXCL5 was the independent risk factor of poor prognosis in patients with gastric cancer(P< 0.05).The concentration of serum CXCL5 in gastric cancer patients(985.46 ng/L) was higher than in healthy controls(628.49 ng/L, P< 0.01). High level of CXCL5 was correlated with tumor size(P< 0.05), intravascular cancer emboli(P< 0.05), T staging(P<0.05)and M staging(P< 0.05). Conclusion The over- expression and increased concentration of CXCL5 were associated with clinical staging, pathological grade and survival time.CXCL5 may play an important role in the development,invasion and metastasis of gastric cancer. Key words: chemokine(C- X- C motif)ligand 5; Gastric cancer