Abstract: Objective To explore the effect of loneliness on internet addiction among rural left-behind children in Dezhou City,and the mediating role of social anxiety and sense of security. Methods From November to December 2021,883 rural left-behind children in Dezhou City were investigated with children's loneliness questionnaire,children's social anxiety scale,left-behind children's security scale and adolescents' pathological internet use scale,and the data were analyzed. Results The scores of loneliness,social anxiety,security and internet addiction in rural left-behind children in Dezhou City were （33.59±12.56）,（15.81±4.37）,（86.96±21.97） and （2.06±0.63）points,respectively. The loneliness was positively correlated with social anxiety and internet addiction（r=0.38,0.31,both P<0.01）,and negatively correlated with sense of security（r=-0.49,P<0.01）. The social anxiety was negatively correlated with sense of security（r=-0.58,P<0.01）,and positively correlated with internet addiction（r=0.39,P<0.01）. The sense of security was negatively correlated with internet addiction（r=-0.36,P<0.01）. The loneliness significantly positively predicted internet addiction among left-behind children,and social anxiety played a mediating role（β=0.006,P<0.01）. The latter half of the mediating effect（the influence of social anxiety on internet addiction of left-behind children） was regulated by the sense of security,that is,the influence of loneliness on Internet addiction of left-behind children decreased with the increase of security（β=0.007,P<0.01）. Conclusion The loneliness of rural left-behind children in Dezhou City affects internet addiction through social anxiety,and the sense of security moderates the effect of social anxiety on internet addiction among left-behind children.

Key words: Left-behind children, Loneliness, Social anxiety, Sense of security, Internet addiction