Abstract：Objective To explore the effect of cyberbullying on adolescent depression. Methods A total of 430 adolescents, aged 12—16 years, were measured by Internet bullying subscale, loneliness scale, school life satisfaction scale, and Beck self rating depression scale. Results A total of 402 valid questionnaires were recovered, with an effective rate of 93 %. After controlling demographic variables, cyberbullying had a significant positive predictive effect on adolescentdepression （ β=0.58, t=7.59, P<0.001） . Loneliness played a partial mediating role between cyberbullying and adolescent depression （95% CI: 0.03-0.14）. School connection had a significant negative regulatory effect on the mediating effect of loneliness. School connection regulated the second half path of the mediating process （INDEX=-0.003 1, 95% CI: -0.007 4- -0.0001） . Conclusion Cyberbullying can affect adolescent depression through loneliness, and the mediating effect is regulated by school connection.
