Leadership style and organizational culture have changed and progressed significantly under the fast changing knowledge economy during the recent decades, and these are important challenges for managing businesses. Therefore, it is required to redefine characteristics of CEO leadership style and organizational culture in these days. The purpose of this study is to develop and validate scales for the measurement of leadership style and organizational culture. First, as a preliminary investigation, we conducted in-depth interviews with 39 executives and senior managers to develop the items for questionnaires. Second, we conducted formal in-depth group interviews with 72 interviewees and collected completed questionnaires from 387 study participants. To test the convergent validity of the questionnaire items, we conducted an exploratory factor analysis using this sample. The results for the scale measuring leadership style showed that all 28 items were categorized into four factors (LSI: People-oriented, LS2: Visionary and entrepreneurial, LS3: High challenge-seeking and risk-taking, and LS4: Low challenge-seeking and high-control). The results for the scale measuring organizational culture also indicated that all 21 items were categorized into four factors (OC1: People-oriented, OC2: High challenge-seeking and innovative, OC3: Low challenge- seeking and status-quo, OC4: Bureaucratie and top-down). The reliability of the four factors for each leadership style and organizational culture measurement instruments was acceptable. Results of a confirmatory factor analysis conducted to verify the discriminant validity of the instrument items indicated that the four-factor model for leadership style and organizational culture fitted the data significantly better than the two-factor model as well as one-factor model for both measures. Finally, as an additional test, the results of the correlation analysis for both leadership style and organizational culture proved the measurement validity of our study variables. These results of vaüdation tests support the usefulness and practicahty of these variables for future research.