Abstract The purpose of the study: the purpose of this research study attemps to examine the relationship between the types of children's temperament and their social behavior. The instruments used in this study include: (1) Temperament Assessment Battery for Children; (2) California Preschool Social Competence Scale. The teachers of 490 children from 22 kindergartens in Taipei were responsible for filling out all questionnaires necessary. A full exploration of data underwent the following statistical analysyis: cluster analysis and one way ANOVA. The result indicate that: a.There are six types of children's temperament: (a) widespread type; (b) social type; (c) concentration type; (d) easygoing type; (f) quiet type. b.The relationship between the types of children's temperament and their social behavior includes: (a) eastgoing type children's working competence is significantly higher than all the other 5 types of children. (b) both eastgoing type and social type children's initiative is significantly higher than widespread type, concentration type, and quiet types of children. (c) both easygoing type and social type of children's understanding toward human relationship is significantly higher than widespread type, quiet type and concentration type children. (d) both easygoing type and social type of children's polite social conduct is significantly higher than widespread type, quiet type and concentration type children. (e) both easygoing type and social type of children's reaction in unfamiliar situations is significantly higher than widespread type, quiet type and concentration type children. (f) both easygoing type and social type of children's language ability is significantly higher than widespread type, quiet type and concentration type children.