Objective: To explore the relationship between pubertal knowledge-attitude-practice(KAP) and quality of life (QoL) of left-behind children in adolescence, and to provide a scientific reference for making measures to improve QoL of left-behind children. Methods: In December 2017, 3 524 left-behind children from 5 primary schools and 5 middle schools in Chongqing were selected by stratified cluster sampling method carry out the Quality of Life Scale of adolescent children and the Questionnaire of Adolescent Knowledge and Belief. Results: The scores of total QoL, physicaland social dimensions of left-behind children[(140.81±17.19)(30.05±5.07)(50.99±8.32)points, respectively]were lower than those of non-left-behind children[(141.81±17.53)(30.35±5.06)(51.73±8.44)point, respectively](P<0.05). Gender, School period, puberty timing, family rearing pattern and economic status had significant influence on the QoL of left-behind children (P<0.05). The adolescent attitude and behavior had a positive effect on total QoL and the scores of physical, psychological, social and adolescent dimensions of left-behind children(B=0.62, 0.08, 0.11, 0.30, 0.13；0.77, 0.11, 0.20, 0.26, 0.19, P<0.01); and knowledge had a positive effect on the adolescence of QoL(B=0.04, P<0.01). Conclusion The adolescent attitude, behavior and quality of life of left-behind children were positively correlated. Strengthening adolescent health education for left-behind children, focusing on conveying correct adolescent attitude to students, and promoting the transformation of correct attitude to positive practice, can improve the QoL of adolescent left-behind children.

Objective: To determine the relationship between peer attachment and quality of life among adolescents in Chongqing, to provide scientific basis for intervention of quality of life. Methods: A total of 6 073 respondents were selected from 5 middle schools and 6 primary schools in a district of Chongqing in December 2017 by stratified cluster sampling method. The revised Chinese version of Adolescent Attachment Questionnaire (IPPA-R) Peer Attachment Subscale and Adolescent Children s Quality of Life Scale were used to conduct the survey. Results: The total score of life quality of students with secure attachment type (144.97±17.39) was significantly higher than that of students with insecure attachment type(136.45±17.75)(t=18.90，P<0.01). The scores of four dimensions of life quality of students with secure attachment[(30.40±5.11)(39.42±6.42)(53.45±7.99)(21.73±3.69)] were significantly higher than those of students with insecure attachment[(29.54±5.15)(37.87±6.66)(49.02±8.69)(20.02±3.60)](P<0.05). Multivariate stepwise regression analysis showed that peer attachment was correlated with physical, psychological, social, adolescent dimensions and the total score of life quality(B=0.28，0.03，0.05，0.14，0.05，P<0.05). Conclusion Adolescent peer attachment is positively correlated with the total score and specific dimensions of life quality. Improving the safety of peer attachment is helpful to improve life quality among adolescents.