Abstract. The power distribution of Member States of EU represents a problem of major importance concerning the future decisional structure. The article analyses the distribution of vote power in the CM, showing the influences of states over the decisional process as well as the modification that appears along with the enlargement. Within the organizations with vote decisions systems, an efficient decisional process supposes the knowledge of the possibilities that exists in formation of coalitions in case of a proposal. Starting from the analysis realized at EU level, the article presents a case study regarding the distribution of vote power and its influence over the decisional process in Romanian Parliament during 1996-2004.

Keywords: decisional making process; coalitions formation; voting game theory; Shapley-Shubik index; Banzhaf index.