Abstract: This paper mainly focuses on the approach of obtaining camera orientation parameters of remote sensing image pairs from different orbits.The fundamental mathematical models of obtaining camera orientation parameters from collinearity equations and coplanar conditions are discussed in detail.To combine the two models,spatial resection model based on coplanar conditions is modified.Results of the combined model can be obtained with adjustment by observation equations.Algorithms of how to calculate the initial values of orientation parameters are also addressed.The proposed approach is tested with a stereo image pair and some results are given.