Ionic　liquids　(ILs)　are　molten　organic　salts　consisting　of　organic　cations　and　weakly　coordinating　organic/inorganic　anions　at　room　temperature.　ILs　have　excellent　physical　and　chemical　properties　such　as　high　thermal　stability,　high　combustible　temperature,　high　miscibility　with　organic　compounds　and　so　on,　making　them　good　candidates　for　high　performance　lubricants　and　lubricant　additives.　The　functional　designability　of　ILs　makes　them　novel　lubrication　materials　that　can　break　through　the　bottleneck　of　the　active　control　of　friction　and　lubrication.　This　paper　firstly　briefly　introduces　how　to　design　the　physical　and　chemical　properties　of　the　ILs　required　for　different　friction　conditions　by　bonding　specific　cations　with　anions.　Then,　the　lubrication　mechanisms　of　ILs　as　base　lubricants　and　additives　for　oils　and　water　are　focused　on.　The　correlation　between　the　structure　of　ILs　and　the　lubrication　results　are　established,　which　can　guide　the　structural　design　of　ILs　in　different　applications.　The　response　behaviors　of　friction　characteristics　under　external　electric　fields　are　analyzed,　which　can　provide　a　theoretical　basis　for　the　intelligent　control　of　friction　based　on　ILs.