Drawing on several theoretical perspectives (e.g., individual motivation, behavioral decision-making, social exchange theories, and neoclassical economics theories) from different disciplines (e.g., organizational psychology, strategic management, and economics), this book developed a perception-based approach to examine the effects of employees' perceptions and/or attitudes on their reactions to organizational change. Based on data obtained from two samples of respondents from two different settings (i.e., a downsizing in Study 1 and a privatization in Study 2), this book found significant relationships between perceptions and/or attitudes and resistance to change and/or support for change. Therefore, the findings provide some empirical support for the perception-based view of the employee. Based on the findings in this book, it is probable that we will be able to develop a variety of tools for predicting employees' reactions to change. In addition, the findings will be informative for consultants and managers, as a way to improve the current change management practices in dealing with employees' resistance to change.