RESUMEN
OBJECTIVES: This study aimed to investigate the validity and standardize the Spielberger State-Trait Anxiety Inventory (STAI) in middle and high school students and find the factors which influenced their anxiety. METHODS: 1,033 middle and high school students were selected randomly from 7 regions around the country. The State-Trait Anxiety Inventory (STAI) was applied in all subjects and the Beck Anxiety Inventory (BAI) was applied with it to calculate the coexistence validity. To find the causes of adolescent anxiety, Beck Depression Inventory (BDI), Subjective Happiness Scale, The Satisfaction With Life Scale, Rosenberg Self-Esteem Scale (RES), Parent-Adolescent communication family inventories, In family social scene were all applied and correlation with STAI was investigated. RESULTS: Reliability issues, such as internal coherence, the coherence between specific phobia and anxiety state were satisfactory and the coexistence validity with BAI was high. The result of factor analysis shows that factor structures were similar to previous studies. High school students showed higher anxiety levels than middle school students, and girls higher than boys. For socio-economical factors, poverty and poor grades related to higher anxiety. Among psychological factors, happiness and selfesteem showed high correlation with anxiety. CONCLUSION: The State-Trait Anxiety Inventory (STAI) showed high validity and reliability in middle and high school students and proved itself a reliable scale. When treating their anxiety, age, sex, socio-economical and psychological factors should all be considered.