Abstract: A nonlinear formula is derived for tandem strip cold rolling process based on Bland-Ford-Hill model of rolling force and the deformation resistance model in view of both the plastic deformation of workpiece in deformation zone and elastic deformation at either the entrance or the exit of the zone. The formula is given in terms of indirect substitution, i.e., substitute the measured rolling force values for the corresponding unknown parameters in the deformation resistance model and then solve the formula to obtain the actual value of the resistance to deformation. Further, the adaptive learning coefficient of the deformation resistance model can therefore be obtained by way of exponential smoothing average. The application results showed that the accuracy and stability of the actual value of the resistance to deformation obtained in such a way are available to meet the requirement of on-line process control and improve the calculation accuracy of both the deformation resistance model and rolling force model.