The work aims to study effects of ionic liquids on film-forming capability as well as friction and wear properties of basic lubricants as additives. With poly-α-olefin (PAO8) and lithium-based grease as basic additives, and quaternary phosphonium chloride ionic liquid as additive, an experiment was performed with UMT-3 multi-functional friction and wear tester, tested sample surface was analyzed with scanning electron microscope (SEM). Meanwhile, film thickness was measured optical interference point-contacting lubricating oil film thickness tester. Effects of the ionic liquids on friction and lubrication properties of basic lubricants as additives were evaluated by comparing friction coefficient, film thickness and wear scar of the basic lubricants with those of basic lubricants containing the ionic liquids. Compared with base oil and base grease, ionic liquids could effectively reduce friction and wear as additives. Lubricants containing ionic liquid additives had higher oil film thickness, and the effect on film thickness was more obvious especially in high case. The starvation condition could be relieved apparently by adding ionic liquids. Ionic liquid additives can effectively reduce friction and wear while improving lubricating property.