Objective To investigate the relationship between body weight, body dissatisfaction and depression symptoms among Chinese children. Methods The fasting body weight and height of the third and fourth grade students (n=3886, aged 9 or 10years) from 20 schools in Beijing, China, were measured, and the students were asked to choose the figures of body image and to complete the self-reported children's depression inventory (CDI) questionnaire. Results The CDI Cronbach's alpha was 0.81. The total CDI score was 9.60±7.50, 13.2% of children (boys 16.7% vs girls 9.5%) were at risk of developing depression symptoms. Overweight girls, but not boys, had significantly higher total CDI score than their normal weight counteparts. Both obese girls and boys showed a higher negative self-esteem score. More than one fifth underweight girls still wanted to be thinner while more than one third obese boys still wanted to be heavier. Children who wanted to be thinner showed slightly higher scores of ineffectiveness and negative self-esteem. After introducing the body dissatisfaction into the model, overweight was still associated with total CDI score among girls and obesity was still associated with negative self-esteem among both boys and girls. Conclusion Overweight girls show a significantly higher depression symptom score than their normal weight counterparts, which maybe partially explained by body dissatisfaction. Obese boys and girls are both more likely to suffer from low self-esteem, which is partially explained by body dissatisfaction.