. The volume fraction of inclusions is one of the most critical parameters of polymer composites, which affects or even decides the mechanical behaviour of the materials. A procedure to calculate the volume fractions of inclusions of any size and shape distributions in polymer composites is introduced. It combines the capabilities of a digital processing technique to obtain configuration parameters of inclusions and of a statistical analysis which determines their volume fractions.The measurement principles and the basic procedures of the method are explained in detail. The procedure has been validated on simple shapes. The subsequent analysis is carried out using the method and is shown to be stable in some cases.