Effect of Ti addition on oxidation behavior of Ni-Cr-W alloys was systematically investigated by isothermal oxidation in air. The oxidation rate is accelerated by Ti addition, due to that Cr₂O₃ vacancy density is increased by Ti⁴⁺ occupies Cr³⁺ position, which promotes the formation of Cr₂O₃ scales. Ti addition induced the formation of TiO₂ but inhibited the formation of Ni oxide. Ti segregated on the external Cr₂O₃ scales after oxidation for a period time. Besides, internal oxidation and nitridation were found in both alloys containing Ti. The depth of internal oxidation and nitridation increases with the increase of Ti content.