By using molecular dynamics (MD), we study the course of behavior and constitution of lipid vesicle in order to be able to recreate the measured results obtained in previous experiments. Simulated lipid vesicles are composed of thousands of DSPC lipid molecules. All preformed vesicles have a mean radius of around nine nanometers and interact with the watery environment. We use coarse grain molecular dynamics (CG-MD) simulation method. The CG-MD simulations are run, on multicore parallel computer, up to 30 ns of simulated time. We show that created vesicles remain stable throughout the whole simulated time, but possess an intrinsic defect of having voids in between the two monolayers, probably due to not taking into account different effective sizes of DSPC lipid molecules in the two monolayers.