This paper presents the results of numerical investigation concerning peeling failure of stiffened composite panel under pure bending. A finite element model which consists of continuous shell elements and cohesive elements is developed using ABAQUS finite element code. In the model, Hashin criterion is used to determine the interlaminar damage; and the debonding between skin and stringer flange is simulated via cohesive elements. Failure of stiffened composite panel under pure bending is investigated. Some conclusions are obtained based on the results. The finite element model is so useful that the peeling load and peeling strength of stiffened composite panel can be well predicted.