Abstract: It has commonly been accepted that using a prestressed concrete girder of continuous spans, rigidly supported to from a bridge is a better means for laoge span cable-stayed bridge. According to this principle and using second order theory, formulation of the first order and second order geometric stiffness of the space beam elements and the tangent stiffness of the parabolic cable elements already obtained, and developed the "XZQNCX" programs, which was used to check a series linear and nonlinear calculation. Through comparison, We found that is deficiency to use a single coefficient of modification. And in order to improve the design and construction accuracy, nonlinear analysis can not be ignored.