Exocytosis is an important process in intercellular traffic. In this process, vesicles containing chemical messengers fuse with the plasma membrane, and release their contents through a pore formed between the two membranes. The dynamics of the deformation of the membrane during this process directly affects the kinetics of messenger secretion (e.g., by affecting pore stability or pore expansion velocity). However, because of the small size of pores, direct experimental information on pore evolution is not yet available. Earlier models linking observable experimental information (i.e., rate of chemical messenger release) to the dynamics of membrane and the surrounding fluid required the pore expansion velocity as an input parameter. In order to predict pore evolution, and to provide a more accurate model of the mechanics of the bilayer we have developed a continuum model for the bilayer deformation after pore formation based on the model of Evans and Yeung (E. Evans, A. Yeung, Chem. Phys. Lipids, 1994). The bilayer is modeled as two fluid monolayers that can slide on each other resulting in interlayer friction force. Each of the monolayers is modeled as an elastic sheet with resistance to bending and stretching. Due to the submicron length scale in this process, the interlayer friction dominates the viscous forces in the surrounding fluid; therefore, modeling the bilayer without the presence of surrounding liquid is a good approximation. To obtain a numerical solution the resulting equations are discretized and solved according to finite difference schemes, and the interface shape is captured by cubic splines. We present the model and the result of a series of validation tests such as oscillating ellipsoidal vesicle and relaxation of fused giant vesicles. This research was supported by the NIH grant R01 EB000508-01A1.