Abstract: 〕Objective: To explore the sexual maturity status of fourth to sixth grade primary school students and their knowledge,
attitudes and behaviors relevant to the endocrine disrupting chemicals （EDCs） in Diannan Town, Dali Bai Autonomous Prefecture.
Methods: Stratified random sampling method was used to select students from fourth to sixth grade in two primary schools in Diannan
Town, Dali Bai Autonomous Prefecture, and a questionnaire survey was carried out. Results: There were statistically significant
differences in the scores of EDCs-related knowledge and attitudes among students of different grades, ages and girls whether they had
secondary sexual characteristics and menarche (P<0.05). The fourth grade and sixth grade students had better EDCs-related
knowledge and attitudes than the fifth grade students. Girls without secondary sexual characteristics and menarche had better EDCsrelated
knowledge and attitudes than girls with secondary sexual characteristics and menarche. There were statistically significant
differences in the eating behavior habits of girls at the age of menarche (P<0.05). Girls who had menarche at the age of 12 and 13 had
better eating habits than girls who had menarche at the age of 11. Conclusion: Girls who had menarche at the age of 11 had poorer
dietary behavior habits; the fifth-grade students, the 11-year-old students, the female students with secondary sexual characteristics
and menarche had a poor attitude towards EDCs knowledge and more exposure to EDCs. Effective prevention and treatment programs
should be developed to cultivate students′ good daily living habits and strengthen the education of EDCs related knowledge.

Key words: endocrine disrupting chemicals, sexual maturity, knowledge, attitude and practice, primary school students