The purpose of this study was to construct the social anxiousness scale for children (SASC) and to clarify its relation between social anxiousness, self-consciousness and social self-efficacy. In the first study, 341 fourth, fifth, and sixth graders answered the original SASC items. Eighteen items was selected on the basis of item-total correlation, Cronbach's α, and factor analysis. In the second study, 195 fourth, fifth, and sixth graders answered the SASC and social anxiousness subscale of General Anxiety Test (GAT), and teacher rating of children's social anxiousness was obtained in order to test validity for SASC. Between the SASC score and GAT score and teacher rating, significant correlations were obtained. Add to this, public self-consciousness and social self-efficacy were measured, too. SASC score was positively correlated with public self-consciousness score, and negatively correlated with social self-efficacy score. It was concluded that social anxiousness might be partly determinated by public self-consciousness and social self-efficacy.