Rolling process is one of the most popular processes in manufacturing industries, such that almost 80 percent of metallic equipment has been exposed to rolling at least one time in their production period. Among all kinds of rolling processes, flat rolling is the most practical. In industrial countries, about 40-60 percent of rolling products are produced with this type of rolling. Increasing demand for thin flat products with high quality and without any shape defects has led to high importance of rolling process. During the rolling process of thin ?at product, i.e., long metal strips, the development of residual stresses, acting predominantly in the axial direction of the strip, are hardly to avoid. They are originated by even very small differences in the opening of the rolling gap along the width of the plate leading to small variations in the thickness reduction and as a consequence of the incompressibility of plastic deformations, to axial stresses. The problem of excessive residual stress in cold rolled ?at products represents an important source of production loss. Thin plates are prone to buckle even under small compressive membrane forces. Hence, it happens frequently that during the release of the global tensile force buckling and post-buckling can be observed leading to wavy plates. Certainly, the best way to achieve better efficiency and accuracy and also control of every process including rolling process is identification of the basic parameters governing the process and the relations between them in order to study the effect of each parameter on the whole process. In this project, after studying various types of shape defects and the cause of formation of waves in rolling process, a model of flat rolling process employing ABAQUS software is created in order to recognize the factors affecting the non-uniform deformation of plates. After modeling and verification of the model with theoretical results, the deformation of the rolled plate in the roll-gap for the case of the uniform entry and exit profile and the effect of rolling parameter on the variation of longitudinal residual stresses is studied. In this case, it is found that in addition touneven geometrical factorinfluencing the plate quality, variation of forming condition along the plate width as a result of different boundary condition lead to heterogeneity of deformation despite the fact that variation in residual stresses may be very low, It is shown that this condition plays an important role in buckling of thin flat rolled products. To examine the relation between sheet thickness profile changes and the final plate shape, metal flow in deformation area for different crown plate models is studied. The results of simulation show that transversal flow of metal in roll-gap has great influence on residual stress for different crown shapes. It is shown that the transition from flatness to bad shape for specific ratio of output thickness to the width of plate, occur as a result of thickness profile changes and also it has shown that critical crown ratio changes for long-edge shape is smaller than long-middle shape. Keywords: Flat Rolling, Shape Defects, Residual Stress, Finite Element Method