Efficiency is what makes todays rolling units different from those of 50 years ago. High rolling speed and decent product quality are the two important factors in the cold rolling industry. Self-excited vibrations or chatter actually limits the speed of rolling and greatly affects the product quality. This phenomenon is directly affected by the friction between the roller and the sheet which is controled by lubrication. The purpose of this study is to investigate the effect of the lubricant parameters in a conventional range on the self-exited vibration of tandem cold rolling mills in order to achieve a better understanding of the chatter phenomenon. Thus, one would be able to apply these considerations in order to fabricate an appropriate lubricant in subsequent research works. In general, two models have been proposed to simulate the vibrations in rolling mills: a simple friction model and an unsteady lubrication model. The long duration of simulation runs is the main challenge of examining the oil parameters using the unsteady lubrication model. Since determining the critical speed can be attained by a trial and error approach, each of the experiments must be repeated several times to achieve the chatter speed. Therefore, in this study a series of experiments has been designed using Taguchi method based on the unsteady lubrication model. Then, in order to study further, parameter interactions have been investigated by using a full factorial design. Also, in the supplementary section, the effect of roller and plate parameters such as elasticity modulus and surface roughness of the work roll, and adhesion coefficient of surface interaction have been investigated. The results show that the chatter speed is in direct relationship with the pressure-limiting shear stress coefficient of the lubricant, but the viscosity and the pressure-viscosity coefficient can have a positive or negative effect on the chatter speed due to the pressure-limiting shear stress coefficient magnitude. In addition to the lubricant parameters it was concluded that the chatter speed has a direct relation with the surface roughness of the work roll and the adhesion coefficient of the roller and plate, and an inverse relation with the elasticity modulus of the work roll. Key words : Cold Rolling, Chatter Vibrations, Lubricant Parameters, Lubrication, Design of Experiment