As an important synthetic methodology for aromatic aldehydes and ketones,selective oxidation of benzyl C—H bond plays a key role in organic synthesis. In this paper,the recent progress of selective oxidation of benzyl C—H bond in liquid phase was summarized from the points of polyoxometalates catalyzed system,metal catalyzed system,N-hydroxyphthalimide catalyzed system,bionic catalyzed system and new type catalyzed system.