RESUMEN
Objective To explore the distribution of temperament types and its related influencing factors of school-age twins.Method Childhood temperament were evaluated by standardized Middle Childhood Temperament Questionnaire (MCTQ) in a total of 125 pairs of 8 to 12 years old twins,and temperament related factors were measured by FACES Ⅱ-CV.Results The majority of temperament types of school-age twins were easy and intermediate-low.Easy,intermediate-low,difficult,intermediate-high and start-to-warm up took a percent of 41.6％,38.0％,11.2％,6.4％ and 2.8％,respectively.The heritability of temperament types was 0.454.The distribution of temperament types were influenced by the family cohesion,parenting rearing style,zygotic,age,father's occupation,mother's educational level and the method of delivery.Conclusion The temperament types of school-age twins were both influenced by genetic and environmental factors.