Abstract: An effective algorithm for calculation of the sectional properties of thin-walled bars with generalsections is presented in the paper. Based on the principle of maximum shear strain energy, the governing equations with nodal sectional coordinates as unknowns are established. An effective solution technique which incorporates the concept of FEM (finite element method) is provided to calculate the primary unknowns. As a result, the sectional properties can be obtained conveniently. A microcomputer program CPTBGS (A Computer Program for Cross-sectional Properties of Thin-walled Bars with General Sections) is developed in FORTRAN language.Several examples are provided to validate the proposed method and the developed program CPTBGS.