Abstract: In our previous work, we reported that the initial crack spacing depends on the colloidal particle size. However, crack patterns must be related to the mechanical properties of the drying films, which has not been sufficiently explored. The fracture theories for drying colloidal films and the crystal fracture theory are used in this paper to study of a drying film formed by the controlled vertically drying deposition. We found that the shear modulus also depends on colloidal particle size. Further more, comparing our results with the variation of the dry particulate film's shear modulus, a remarkable discrepancy is found for this size-dependant behavior while the particle radius decreases. This remarkable discrepancy shows that the mechanical behaviors of drying particulate films are determined not only by the structure of the solid part but also by the liquid part.