Transition-metal catalyzed C-H functionalization is a straightforward and efficient way to construct C-C and C-X bonds. However, these transformations usually require stioichiometric or excess amount of external oxidants to oxidize low valent metal and regenerate the active catalytic species. The use of the oxidizing directing group, which contains some special group acting as the internal oxidant, can avoid the troubles arousing from the external oxidants and make the reaction process more simple and efficient. Recently, increasing number of novel oxidizing directing groups have been designed and diverse kinds of reactions have been developed. This approach can be used to synthesize kinds of heterocyles or highly functionalized products under external oxidant free conditions.