This investigation evaluates the lubricities of Trihexyltetradecylphosphonium dicyanamide and Trihexyltetradecylphosphonium tricyanomethanide and discusses the tribo-decomposition behavior using quadrupole mass spectrometer (Q-MS). This investigation focused on the ability of these ionic liquids to be used as novel lubricant oils and lubricant additives. Both ionic liquids exhibited better lubricities compared to conventional ionic liquids. Q-MS analysis indicated that both ionic liquids underwent tribo-decomposition on worn surfaces. The substances derived from cation were identified immediately after the friction test was initiated. Tribo-film was composed with cations and anions and the surface analysis undertaken following the friction tests found it to be rich in anions. This study indicates that these ionic liquids may be suitable for application as lubricant additives.