In order to understand the shrinkage behaviour of spheroidal graphite (SG) iron during solidification, a volume change kinetic model was set up to simulate the volume change during the eutectic solidification, which was presented in an earlier paper. Furthermore in the present work experiments were carried out for comparison with theoretical prediction. The microstructure of the mushy zone during the solidification of SG cast iron was obtained by the quenching method and analysed by normal metallography and image analysis. The results show that the mushy zone exists in front of the interface between the liquid and the solid. The study by quantitative stereology shows that the graphite fraction in the mushy zone has the same trend as that of the theoretical prediction and the silicon content in cast iron strongly influences graphitization during the solidification. A heat-transfer model to stimulate the heat transfer of the experimental apparatus was developed. A modified Rappaz’s model was used to simulate the eutectic growth under fully equilibrium conditions. The theoretical prediction has been compared with the experimental results, and found to be in good agreement with each other.