Abstract: The prevalence of anxiety disorders peaks during adolescence and has a severe impact on adolescents' health both physically and mentally. The current understanding of the pathogenesis, development, and intervention of anxiety in adolescents mainly relies on the work related to fear processing at the conscious level. However, these works ignore the important fact that the function of the prefrontal lobe and the function of top-down control under the cortex are not mature enough in adolescents. Therefore, applying a top-down mechanism to clinical treatment for adolescents may exist limitations. Furthermore, exploring automatic fear processing may help to extend the knowledge about the pathogenesis of anxiety in adolescents. This is the first research combined with unconscious perception to explore the occurrence, development, and mechanism of anxiety in adolescents. Recruiting adolescents which are in anxiety/health or vulnerable to anxiety as subjects and integrating paradigms used for examining unconsciousness, we aim to explore: 1) the occurrence and development of unconscious fear processing as well as its underlying neural mechanism in adolescents; 2) the role of unconscious fear processing in the development of anxiety in adolescents; 3) the noninvasive intervention for unconscious fear in adolescents.This project will provide scientific support for the prevention, recognition, and intervention of anxiety in adolescents and to promote all-round development of adolescents in physical and mental.