This study was designed to construct a new self-consciousness scale for Japanese children, examine the reliability and validity of the scale, and investigate the relations between self-consciousness and seven personality traits: shyness, self-exhibition, loneliness, and four kinds of perceived competence. A questionnaire consisting of twenty-eight self-consciousness items, 90 items concerning the above ersonality traits, and 25 social desirability items was administered to 424 5th-and 6th-graders, and factor analysis concerning self-consciousness items revealed 2 solutions as predicted; one factor was nemed public self-consciousness and the other was named private self-consciousness. The reliability and validity was highly estimated. Public self-consciousness score was positively related to the scores of shyness, self-exhibition, and loneliness. Private self-consciousness score was negatively related to the scores of shyness and loneliness, and also positively related to the scores of self-exhibition and four kinds of perceived competence. Results concerning private self-consciousness were inconsistent with the previous studies. It was understood from the developmental point of view.