Human resource is an important resource to achieve organizational mission (McGregor, 1960). The impact of strong competition, dramatic changes in the external environment, the business enterprise has a certain degree of impact and influence. How to operate with sustainability in this changeable environment of intense competition would be the prior goal that a firm is pursuing. Under the context of rapidly-changing industrial paradigm, leaders face the critical issue of how to attract excellent employees and keep them dramatically influences the competitiveness of the company. The purpose of this study was to investigate the relationships among leadership style, work motivation, and job involvement, and also use the oranizational justice as a moderator. This research tries to find out the moderating effect of organizational justice on work motivation and job involvement. This research targeted the top 1000 companies in manufacturing industry and top 500 companies in service industry which were according to the year 2008 ranking of the Common Wealth Magazine, of that, 417 valid samples were returned. The study adopts the following statistical analysis techniques: The confirmatory factor analysis (CFA), the reliability analysis, the descriptive statistics, the independent t-test, the one-way ANOVA, the correlation analysis, and the hierarchical regression analysis. The finding were as follows. 1. Both transformational and transactional leaderships show significant positive effects on the extrinsic motivation. 2. Both transformational and transactional leaderships show significant positive effects on the intrinsic motivation. 3. The extrinsic motivation shows significant positive effects on the job involvement; but the intrinsic motivation shows no effect on the job involvement. 4. Both transformational and transactional leaderships show positive effects on the job involvement. 5. The extrinsic motivation has mediated effect between leadership style and job involvement. 6. The procedure justice has moderated effect between intrinsic motivation and job involvement. This study concludes by discussing for the implications of major findings, which would be a reference to the academy and industries, and make suggestions for further studies.