This study is an empirical attempt to investigate the relation between principal's leadership and quality factor of decision making in the elementary school. Therefore, the purpose of this study is to examine the relationship among the principal's leadership, quality factor of decision making and sub-variables. The specipic object of this research are (1) to investigate the relationship between or among variables identified in this study, (2) to examine the infuences of these variables on one another, and vice versa. In order to accomplish the subjects, five sub-variables has been identified on the basis of subvey of the literlature concerned. The sub-variables of transactional leadership and transformational leadership to say quality factor of decision making involves these derterminents, namely decision maker, participation of members and communication. On the basis of theoritical background, two research problems have been formulated for this research purpose. Research Problem I. There can be positive significant correlations among principal's leadership, quality factor of decision making and sub-variables with one another. Research Problem Ⅱ. The leadership variables can have different influences on the sub-variables quarity factor decision making. From the analysis through statistical procedures, the following conclusions can be drawn. 1) All the sub-variables studies show positive significant correlations. This demonstrates that principal's leader variables are influential to quality factor of decision making variables. 2) In the case of influences of principal's leadership variables quality factor of decision making variables, transformational leadership is shown to be more influential to such quality factor variables as decision maker, participation of members, communication than transactional leadership.