Lead, a common heavy metal pollutant existent in the environment, is toxic to multiple organ systems of the body. To explain the toxic effects and mechanism of lead on immune system, various studies including epidemiological investigations and animal experiments have been conducted over past two decades. Accumulating evidence indicates that lead is immunotoxic and influences both innate and adaptive immunity. Lead decreases the phagocytic activity and increases the oxidative stress of macrophages. Lead also inhibits cell-mediated immunity and promotes humoral immunity. This review summarized related recent literatures.