【Objective】 To investigate how the preschool children's diet behaviour influence their nutritional status in Shenzhen. 【Methods】 Stratified cluster sampling method was adopted to select suitable objects during March to June,2009.Before investigating,the investigators were gathered and trained by unified standards.Every child was investigated by one self-made questionnaire.10 138 preschool children were investigated,and 8 920 questionnaires were effected. 【Results】 The prevalence of simple obesity of preschool children in Shenzhen was 9.0%,the underweight was 0.6%,the stunting was 1.6%,the wasting was 0.9% and the anemia was 2.53%.There were risk factors of simple obesity such as listening to music,watching TV or playing while eating,short dinner time,disgusting chewing solid food and eating snacks before meal,liking to eat out et al.What's more,these behaviors as unfixed dinner time,dislike to chew solid food,refusing eating,less to go out for dinner were the risk factors of malnutrition and anemia of preschool children. 【Conclusions】 The study suggests that the preschool children' nutritional status is fine in Shenzhen,and some diet behavior were risk factors of obesity,underweight,stunting,maransis and anemia separately.