BackgroundIn recent years， the incidence of non-suicidal self-injury （NSSI） behaviors among adolescents has been increasing annually. Self-esteem and alexithymia are strongly associated with NSSI behaviors， and alienation is closely linked to both self-esteem and alexithymia. However， there is limited research on the relationship between alienation and NSSI behaviors among adolescents in China. ObjectiveTo analyze the relationship between alienation and NSSI behaviors among adolescents， and to explore the factors influencing NSSI behaviors in this population， so as to provide insights for the prevention and treatment of NSSI behaviors in adolescents. MethodsAdolescents admitted to the Department of Psychiatry and Psychology at the 923^rd Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from September 1， 2021 to March 1， 2023， who met the diagnostic criteria for NSSI in the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5）， were selected as the study group （n=60）. Concurrently， middle school students from Nanning were recruited as the control group （n=60）. Participants were assessed using Adolescent Self Harm Scale （ASHS）， Rosenberg Self-Esteem Scale （RSES）， Toronto Alexithymia Scale （TAS） and Adolescent Students′ Alienation Scale （ASAS）. Pearson correlation analysis was employed to examine the relationships between scale scores in the study group， and Logistic regression analysis was used to identify the influencing factors of NSSI behaviors among adolescents. ResultsThe RSES score of the study group was significantly lower than that of the control group （t=-7.033， P<0.01）. The TAS and ASAS scores of the study group were significantly higher than those of the control group （t=5.591， 8.124， P<0.01）. The ASHS score was negatively correlated with RSES score （r=-0.410， P<0.01） and positively correlated with ASAS score （r=0.555， P<0.01）. The RSES scores of the study group were negatively correlated with TAS and ASAS scores （r=-0.317， -0.590， P<0.05 or 0.01）. Logistic regression analysis showed that being female （OR=0.714， 95% CI： 0.042~0.709） was a protective factor for NSSI behaviors among adolescents， while high alienation （OR=1.028， 95% CI： 1.013~1.043） and residing in rural areas （OR=6.692， 95% CI： 2.038~21.967） were risk factors for NSSI behaviors among adolescents. ConclusionAlienation was positively correlated with NSSI behaviors in adolescents. Female adolescents had a lower risk of NSSI behaviors， while those with higher levels of alienation or residing in rural areas were more prone to NSSI behaviors. ［Funded by Self-financed Scientific Research Project of the Health Commission of Guangxi Zhuang Autonomous Region （number， Z20210656）； Self-financed Scientific Research Project of the Health Commission of Guangxi Zhuang Autonomous Region （number， Z-A20231057）］