This paper presents an Intelligent Fixturing System (IFS) which can adaptively adjust the clamping intensities to achieve minimum deformation of the workpiece according to the cutter position and the cutting forces during the entire machining process. The concept, architecture, control scheme, models and methodologies for the IFS are described. Using off-line simulations and on-line experiments, the performance of the IFS is evaluated and verified. Since adaptive clamping forces appropriate to the dynamic machining environment are provided, the proposed IFS offers higher quality of machined parts and more flexibility to disturbances. This system is suitable for application in a high-precision machining environment where a combined optimal machining and fixturing process is required.