Enhanced　oxidation　resistance　is　a　primary　demand　for　the　application　of　refractory　high-entropy　alloys　(RHEAs)　at　elevated　temperatures.　In　this　study,　Al　was　added　to　a　Ti2VZrNb　RHEA　to　partially　substitute　Nb　to　improve　its　oxidation　resistance　and　mechanical　properties.　The　alloy　was　found　to　have　an　increased　oxidation　resistance　by　forming　a　continuous　Al2O3　+　ZrO2　oxide　protective　surface.　At　the　same　time,　the　room-temperature　yield　strength　was　also　increased　by　66%　to　1273　MPa　via　solid　solution　strengthening.　The　low　atomic　mass　of　Al　also　helped　to　reduce　the　density　of　the　alloy　by　8.2%　to　5.44　g　cm(-3).　This　resulted　in　a　high　specific　yield　strength　of　234　MPa　cm(3)　g(-1)　for　the　alloy.　Meanwhile,　the　Ti2VZrNb0.5Al0.5　alloy　also　exhibited　a　high　compressive　plasticity　of　＞50%.　These　values　are　among　the　best　reported　so　far　for　RHEAs.