Abstract: The performance of light wood trusses connected by metal plates was investigated in this paper. A methodology and program was developed to compute the displacements of each joint of light wood trusses caused by slippage of metal plates. Based on the principles of the finite element method, the spring’s series connections was employed to combine two virtual viable stiffness bars and one entity bar into an equivalent equal stiffness bar, thus the unit stiffness matrix and integrated stiffness matrix were established. Computation theory of normal truss structure was then adopted to compute the forces and displacements of the virtual equal stiffness bars after variable stiffness light wood truss connected by metal plates was introduced. MPT Design, which was based on the above theory and Fortran90, was developed to execute the computation. This methodology was proved to be viable by comparing the computed result with the experimental specifications of wooden structure.