Molecular dynamics (MD) simulations were carried out for (i) hydrated bilayers of phosphatidylcholines (PCs): 1,2 stearoyl-sn-glycero-3-PC (18:0/18:0 PC), 1-stearoyl-2-oleoyl-sn-glycero-3-PC (18:0/18:1ω9cis PC), 1-stearoyl-2-linoleoyl-sn-glycero-3-PC (18:0/18:2ω6cis PC), 1-stearoyl-2-lineolenoyl-sn-glycero-3-PC (18:0/18:3ω3cis PC), 1-stearoyl-2-arachidonoyl-sn-glycero-3-PC (18:0/20:4ω6cis PC), 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-PC (18:0/22:66ω3cis PC), and (ii) bilayers of diacylglycerolipid (DG) molecules with the acyl composition identical to that for PCs. The simulation boxes of the PC bilayers consisted of 96 PC molecules and 2304 water molecules (48 lipid molecules per layer and 24 H2) molecules per lipid). The water was modeled by explicit TIP3P water molecules. The head group of the DG molecules was treated as an effective sphere. The interfaces of each DG bilayer were modeled by flat surfaces; no water molecules were present explicitly in the DG bilayer MD simulation boxes consisted of 96 DG molecules. Mass density profiles along the PC and DG bilayer normal for different groups of atoms were calculated. The computer simulation results are compared to one another, to the available experimental data and to other computer investigations of saturated and unstaturated lipid bilayers.