The purpose of the study was to identify the leadership effectiveness according to the principals` integral leadership style in Korean elementary schools. To accomplish this purpose, theoretical review and survey was conducted. Based on the discussion and result of this study, major conclusions are as follows. First, most frequent leadership style generally employed by the principals was integrated one which used together with all of structural, human resources, political and symbolic leadership style, and the next one was employment of single structural leadership style. These results show that the principals need integrated leadership style based on the comprehensive understanding on school organization, and to operate the organization effectively the structural leadership style was many employed by principals. Second, the more leadership styles were employed, the higher the leadership effectiveness was. And, the integrated leadership styles that show high leadership effectiveness usually contained human resources leadership style. These results show that integrated leadership based on diverse and integrated approach was more effcetive than others, and human resources leadership was very important. Third, the leadership effectiveness among individual variables(sex, generation and region) of teachers was very different. So it is desirable that we should appropriate integrated leadership style according to the individual variables of teachers. Based on the above conclusions, major suggestions are as follows. First, in order to further improve leadership effectiveness, integrated leadership style based on the comprehensive understanding on school organization should be employed by principals. Second, there is no leadership style that was effective in all situation. So, appropriate integrated leadership style should be employed according to the individual variables of teachers. Third, on employing leadership styles, principals should keep in mind that almost teachers do their job with professionalism not dependantly but autonomously. Fourth, in order to activate leadership effectiveness, principals should concern teachers` emotion and human resources leadership style.