The German stock corporation has two-tier boards according to the Stock Corporation Act. However, European Company can implement unitary board system. Hence, German legislators have enacted the European Company Implementation Act, namely application of special provisions to the European Company with unitary board. The provisions of board of directors and supervisory board of the Stock Corporation Act are no more applicable. This article will take the German legal experience as example for suggesting reform Taiwan’s regulation of unitary board. Therefore, this article introduces the two-tier boards system of the stock Corporation Act and the unitary board system of the European Company Implementation Act. It also works on analyzing the reform of supervisory board within the Stock Corporation Act.