Double glow plasma alloying of niobium was applied on TiAl alloy in order to improve its oxidation and wear resistances. Microstructure as well as tribological properties at ambient temperature and 600 oC were studied. The results show that a Nb-alloyed layer, about 12 μm in thickness, is formed on the surface of TiAl alloy after plasma alloying treatment. The alloyed layer consisting of AlNb2, AlNb3, Ti2AlNb and pure niobium is compact and homogenous. Under dry sliding condition, the wear resistance at 600 oC is enhanced greatly for Nb-alloyed TiAl and both anti-friction and wear-resistance at ambient temperature are also better than those of untreated TiAl alloy