Vertical rolling has been widely used in the roughing stand of hot strip rolling to improve the precision of slab width which influences the finished product quality significantly in actual production. Double parabolic dogbone function model and corresponding velocity and strain r a t e f i e l d s a r e f i r s t l y p r o p os e d b a s e d o n t h e incompressibility condition and stream function. They are successfully applied to three-dimensional vertical rolling. Using the first variation principle of rigid-plastic material, an analytical solution of slab total power functional in vertical rolling is obtained. Then, the shape parameters and the rolling force are received by minimizing the power functional. The error of shape and power parameters is within 4 % compared with finite element method (FEM) simulation's result and less than 9.5 % compared with other models' result.