Abstract: Based on the differential equations of prestressed curved box girder, a set of the equivalent spatial loads is derived to represent an arbitrary prestress of an infinitesimal element. According to the element stiffness matrix of a spatially curved thin-walled beam and the computational formulas of the fixed-end forces under various loadings, this paper presents the analysis of prestressing effect on a curved continuous bridge by use of the matrix displacement method While calculating prestress losses, the effect of reverse friction is taken into account. An example is provided and the internal forces and deflection ace to prestress on a P.C. curved continuous box girder bridge are calculated it is shown that the method is reliable.