This research, based on literature discussion related to issues on intraorganizational power, aims to discover the critical factors affecting the power of HR department within a firm and measure their causal relation as well as correlation through questionnaires. The questionnaires, being sent to any possible representative firms within each industry on our lists, were distributed in a convenient way. They mainly contain two sets of items, one for the HR department manager, another three for the line department manager. In the HR manager one, the questionnaires has 10 questions on HR departmental power index as dependent variable in our study; in the line manager one, it has 15, 5 and 5 questions on HR effectiveness, Top Management Support and HR Innovativeness respectively as independent variable. Based on our findings after statistical analysis, we conclude the followings: 1. As the HR effectiveness increases, the power of HR department does in the same. 2. As the Top Management Support increases, the power of HR department does in the same. 3. As the HR Innovativeness increases, the power of HR department does in the same.