Abstract: A triangular plate bending hybrid element is constructed according to Reis-ner's principle. It has 9 degrees of freedom and takes, the shear effect into account. The C0 formulation of the thick plate is extended to the thin plate and the"shear locking"phenomenon can be avoided through imposing the discrete type of Kirchhoff's constraints. It is interesting to note that the kind of discrete constraints can be directly imposed by means of Hermite interpolation. This is one of the features which distinguish the paper from ref. [ 5 ]and [ 1 ]. On the other hand, the specific matching between bending and shearing is discussed in the analysis of the thick plate. It is shown that the reasonable matching between bending and shearing complementary energies may be destroyed by inhomogeneous magnification of the discretization errors. Furthermore, a principle of energy regulation is put forward, with the aid of which this matching problem is effectively treated so that the unified analysis of the thick and thin plates is achieved. Finally, numerical examples are given.