Inflammation is a basic way in which the body reacts to infection, irritation or other injury. The key clinical feature of inflammation is redness, warmth, swelling and pain. A series of immune cells and cytokines are involved in the complicated and interrelated events during inflammation to work together to defend the body. Innate immune cells, including phagocytes, NK cells and dentritic cells, are the main effector cells in initiating an inflammatory response. Adaptive immune cells, for example, T cells which take part in the battle at the later phase of an inflammatory response could also temper the initial inflammatory responses during acute infection. On one hand, hosts rely on inflammatory responses to eliminate the pathogen, control the infection within the local site, and induce the adaptive immune response. However, on the other hand, over-reactive and chronic inflammation can also lead to some diseases. Consequently, the study of the mechanism of inflammation might lead to new treatment for patients with inflammation-related diseases.