Extensive studies have been carried out to deal with the stress singularity of V-notch problems in linear elasticity theory. In fact, the plastic deformation consequentially arises in the notch tip region because of the high stress concentration. The solution of linear elasticity is not adequate to explain the fracture failure of V-notch structures. Because of the difficulties of the nonlinear analysis and the singularity behavior, few results are given for the plastic stress singularities of general V-notch structures. In this paper, the plane V-notch structures in a power law hardening materials are considered. The Von Mises yield criterion and the plasticity total theory are adopted when the materials arise in plastic status. Similar to methods used in the elastic analysis, the plastic stress field near V-notch tips is assumed as an asymptotic expansion with respect to the radial coordinate originating from the notch tip. The governing equations of plastic behavior of plane V-notch are transformed to eigenvalue problems of nonlinear ordinary differential equations (ODEs) contained by the stress singularity order and the associated eigenfunctions. Consequently all of the stress singularities who are less than zero and the associated eigenvectors are accurately determined for the plane V-notches with arbitrary opening angle.