Abstract: Prestressed slab-column structure must be affected by lateral restraint when prestressed tendons were being tensioned.The law of this influence was analysed by a test of an actual project.According to compatibility of deformation,an equation set to solve lateral restraint effects for one-storey and multiple-span frame was built up.Based on the basic assumptions,a simplified formula to calculate the secondary shearing force of column was obtained,with which the law of the lateral restraint effects for the project was analysed.The equation set built up at this paper could solve lateral restraint effects of horizontal members more accurately.