The composition of directors and executives has been the subject of much recent discussion, with concern being expressed about corporate governance and management effectiveness. However the majority of research on this subject is limited to an analysis of the impact of the governance mechanism on management. This article intends to analyze other factors that influence the governance mechanism. As an investigation of the board composition and determining factors for directors and executives, this article applies fuzzy synthetic decision method to evaluate four major US corporations. The result provides a theoretical approach to compose an optimal ratio distribution of board directors.