Interleukin-6 (IL-6) is a multifunctional cytokine that plays a central role in host defense due to its wide range of immune and hematopoietic activities and also its potential ability to induce the acute phase response. The high concentration of IL-6 has implication in the pathology of some diseases especially in DHF/DSS patients. This cytokine play a crucial role in the enhanced production of anti-platelet or anti-endothelial cell auto antibodies local or systemic, elevated levels of tPA, as well as a deficiency in coagulation, leading to plasma leakage and bleeding. We describe the pathogenic, characteristic and mechanism of IL-6 during DV infection.