The forward slip in strip rolling was defined as the relative difference between the roll surface speed and strip exit speed. It was always an important parameter because of its significant influence on friction and tension control. In this study a Phantom V3.0 digital high speed image acquisition and motion analysis system was used to record the movement of the roll and the workpiece during rolling. The pictures captured were analyzed to obtain the speeds of the roll and the workpiece along the roll bite, which then yielded the forward slip. The measurement accuracy has been validated by the mass conservation. The maximum relative error of the forward slip was only 1.6 %. The results have shown that the forward slip increased as the reduction increased for both dry and lubricated rolling. The roll speed did not change the forward slip in the case of dry rolling, but the forward slip was significantly reduced with roll speed when lubricated.