Abstract : Civilian contracts applied to shares are intended to transfer, often temporary, different political and financial rights inherent to these shares : the coveted political rights include the right to vote and the share holder to become a director, if the corporation charter so require ; the financial rights allow to enable them to transfer the business and use the shares as guarantee. In making such transfers,practitioners use standard contracts, often from the Civil Code, but also contracts inspired by civiliantechniques who employ techniques civilians, borrow some of their legal systems and pursue the same aims. However, these contracts are not entirely satisfactory : some have a flexible legal system but do not offer sufficient legal certainty, the others are reliable but afflicted by a binding legal regime. The legislator, in establishing the trust, could overcome these drawbacks. But if the trust provides greater legal certainty, it is always at the expense of the freedom of contract. A new reform of the trust isessential.