Objective To explore the relationship between the behavior and social ability development of Chinese urban 2 ～ 3 years old toddlers. Methods The number of 2601 toddlers aged 2～3 years old were involved by random cluster sampling under the cross-sectional study from 14 large-media cities in China and surveyed by Child Behavior Checklist(CBCL 2/3) and Chinese Toddler Social and Emotional Assessment CTSEA) Questionnaire. The multiple stepwise regression analysis was used to analyze the surveyed results. Results In 2601 toddlers,there were 194 toddlers detected positive about the behavior, the rate was 7. 5% , including boys 107 (4.11%) and girls 87 (3. 34%),and there was gender differences in positive rates of the behavior(t = 2.36,P< 0.05). Otherwise,268 toddlers were detected positive about social-emotional ability,the rate was 10.3% .including boys 139 (5.34%) and girls 129 (4.96%), there also was gender differences in suspected positive rates of social-emotional ability(t = 3.60, P<0.01). The multiple stepwise regression analysis results indicated that attacks, damage,depression,withdrawal were correspond correlated with compliance,empathy,prosocial-peer-relations and imitation. Conclusion Cultivating good habits would promote the development of children' s social ability.