Objective  To explore current situation of anxiety and its influencing factors among high school students in Ningbo city, and to provide references for improving mental health of the students.

  Methods  Totally 3 932 students in 4 high schools in Ningbo city were selected with random cluster sampling and were self-administered with a general questionnaire on demographics and mobile phone use and the Self-Rating Anxiety Scale (SAS) between May and June 2015.

  Results  The overall detection rate of anxiety in the students was 19.25%, and the rate for mild, moderate, and severe anxiety was 14.46%, 3.47%, 1.32%, respectively. The SAS scores were relatively higher among the students at the third year of junior high school (37.04 ± 7.53), being a resident student (35.65 ± 7.04), with the internet surfing time of ≥ 6 hours per day (37.42 ± 6.44), being a non-only child (39.82 ± 9.07), with study stress (36.06 ± 7.23), unable to cope with study stress (39.50 ± 8.03), not interesting in study (38.50 ± 8.46), with lower parental education (36.75 ± 7.11), and with parental education of primary school (36.43 ± 6.92). Logistic regression analyses revealed that study stress, cell phone use time, study interest, and being an only child were correlated positively with anxiety; while, parental education level was reversely associated with anxiety among the students.

  Conclusion  Anxiety emotion is highly prevalent and closely relates to study stress and cell phone use time among high school students; the situation needs to be concerned.