Abstract: Abstract: Objective To investigate the prevalence of malocclusion in children aged 6 to 11 years old in 11 primary schools in Harbin,and assess the effects of feeding patterns,breast-feeding duration，bottle-feeding duration ,food habits and oral habits on the occlusal characteristics. Methods The occlusal characteristics of 12087 children were surveyed. The data of gender, age, feeding patterns, duration of breast-feeding and bottle-feeding, food habits and oral habits were collected by questionnaire. Results A total of 12,087 people were investigated, and the number of malocclusions was 7023, with an incidence rate of 58.10%. Statistical analysis found that breast-feeding, bottle-feeding; breast-fed for ＞ 6 months, bottle-fed for over 18 months; Preference for vegetables and fruits,Preference for cereals; lip habits , stretching chin, mouth breathing, bruxism, sleeping habits, family history were significantly correlated with the occurrence of different malocclusion (P > 0.05). Conclusion Children who had diffrent feeding patterns, breast-feeding duration,bottle-feeding duration ,food habits and oral habits were more likely to develop abnormal occlusal characteristics．

Key words: Key words:school children, malocclusion, feeding patterns, oral habits, food habits