Delegation contract after death is able to be made freely by the party on principle of freedom of contract, and this kind of contract would increase according to the social change in recent days. However, the debates on this kind of contract are still insufficient in Korea. The point of the debate on the effectiveness of affairs delegation contract after death is to guarantee the expression of will of the delegating person during his/her lifetime after death. The will of the delegating person during his/her lifetime should be respected, but it would be able to impose the unpredictable damage or obligation on the heir, not the party of delegation contract. In this regard, the problem is how to organize it, thus the new theorization is needed. The heir shall succeed the position and right of rescission of delegating person by affairs delegation contract after death, but the right of rescission would not be allowed or would not be able to exercise in related to respect to the will of ancestor and other systems in some cases. This matter would be shown as the problem how to theorize harmoniously the respect to the will of ancestor, the order of inheritance act and will system in civil law. Thus, this study set the limit being able to respect to the will of ancestor in affairs delegation contract after death as the criterion that dealing affairs would substantially infringe or have some concern to infringe the heir's legal reserve of inheritance.