: Rolling industry is being considered as a one of the most important and profitable industries in the world. More than 90 percent of steel products have been already rolled. Self-exciting vibration of the rolling mills with constant or rising amplitude is called chatter vibration.Chatter phenomenon is one of the major problems in this industry. Chatter or undesirable vibration of the rolling stands, not only affects and degreades the quality of the sheets, but also decreasetheefficiency ofthe rollinglines significantly. Considering large investments in this industry, chatter is an undesirable phenomenon for the owners of this industry. Knowing the identity of self-excited vibrations in cold strip rolling lines and studying the factors that can arise them, has consistently been one of the important aims of rolling technology researchers. This study tries to simulate and recognize the chatter phenomenon to speed up the lines without the occurrence of chatter. A new structural model is developed, which allows rolls to vibrate horizontally. This model is a 2-dimentional model based on the Hue model. It considers 2-degree of freedom for each roll. The horizontal effects come from centerline angle of the work roll and the backup roll which is not perpendicular to the rolling line. Then by studying the interaction between structure and process models chatter vibrations have been simulated. By using the Taguchi method, series of simulations have been designed for various rolling circumstances and by using artificial neutral network the relation between the threshold velocity and other effective parameters has been identified. In the last step of the research, the output speed of the last stand which indicates the production volume has been maximized as the target function. It is worthy to mention that in all steps constraints and constants has been applied to 2-stands cold rolling line by consulting Mobarakeh steel company experts. The results obtained from optimization show more 20% increase in output speed of rolling sheet. For model verification data from two stands reversing cold rolling mill of Mobarake Steel Company (MSC) have been used. Two-stand tandem mill unit is responsible for the reduction of the sheet thickness in the ambient temperature. Incoming coils have thickness of about 2 mm. The coil passes through two 4-roll stands in a regressive way after it has been opened and loses its thickness by 60 – 90 percent as a result of 2 – 3 rolling passes and is coiled by the coiler machine. The second pass is in reverse direct.All the condition of rolling are measured using tens sensors and saved as digital and analogue signals. Then the simulations results were compared to applicable information of 2-stands cold rolling line and an acceptable accordance was observed. For optimization verification, the optimization results were checked in the simulatiuon program which already has been verified by experimental measurements. Keywords: Rolling Industry, vibration, chatter phenomenon, optimization