Abstract: Cryopreserved boar spermatozoa is much less fertile than that of other species, which could be due to damage to sperm membrane lipids during the cryopreservation process. Incorporation of selected lipids improves the survival of boar spermatozoa following cryopreservation. Liposomes were made from lipids extracted from head plasma membrane (HPM) of boar spematozoa or from selected lipids (SL) which contained specific phospholipids. At a fixed lipid concentration, fusion efficiency with spermatozoa as measured by flow cytometry and R18 dequenching was affected by lipid type, sperm concentration and incubation time. SL and HPM improved sperm viability (SYBR-14 and propidium iodide) and motility during cooling to 5C., with SL±egg yolk better than or equal to HPM (P<0.05). Post-thaw, egg yolk showed a strong cryoprotective effect.