Objective  To explore the influencing factors of bullying among early adolescents and to provide a basis for further research and intervention.

  Methods  A computer-assisted self-interview (CASI) was carried out among 187 students aged 10 – 14 years and selected with cluster sampling from a nine-year school in Shanghai city between January and February 2016. Chi-square test, correction for continuity, Fisher’s exact test and multiple logistic regression were employed in the analysis.

  Results  The number of boys and girls reporting the experience of being bullied were 29 (36.3%) and 10 (11.6%); the proportion of boys being bullied was much higher than that of girls (χ² = 13.98, P < 0.001). Univariate analysis showed that the girls with unmarried parents or with parents not living together were more vulnerable to bullying (χ² = 6.64, P = 0.06) and the boys with four or more female friends (χ² = 4.31, P = 0.04), without perceived helps from their teachers (χ² = 10.59, P = 0.001), almost all teachers contacted in the school being female (χ² = 6.01, P = 0.01), knowing some peers being involved in a love affair (χ² = 8.11, P = 0.04), and loving others (χ² = 14.32, P < 0.001) were more likely to be bullied. Multiple logistic regression analysis showed that among the boys perceived doing the best under the help of teachers was a protective factor against being bullied (odds ratio OR = 0.12, 95% confidence interval 95%CI: 0.03 – 0.54); whereas loving others was a risk factor of being bullied (OR = 10.280, 95%CI: 2.245 – 47.068).

  Conclusion  Emotional problems among male adolescents needs to be concerned and school teachers should provide more help to boy students to prevent them from being bullied.