Abstract: A comprehensive two-dimensional model for freeze-drying of materials in vials was presented and solved numerically by the authors,and was examined by experiments in previous works.By the use of the two-dimensional model,the numerical simulation of vial freeze-drying of skim milk is made in this paper.The effects of radial transfer of heat and mass on freeze-drying process of materials in vials are analyzed by using simulating results.The results show that the influence of side heat transfer on freeze-drying process is significant, but the effect of radial transfer of vapor can be ignored.