Abstract: Based on the exact longitudinal displacement for thin-walled curved beams, a general theory for linear analysis of curved beams with any open sections is established in this paper by using the principle of virtual work. The differential equations of equilibrium and natural boundary conditions are given. Two new quantities H_v and H_θ are introduced from which the resultants of the shear flow may be derived conveniently. Its applications in curved beams with commonly used sections, such as I-shape, channel section and H section without any symmetrical axis, are demonstrated and comparisons are made with previous theories.