A composite coating including top-layer( Al) and interlayer( TiO2) was coated on TA2 through magnetron sputtering and micro-arc oxidation,respectively. The formation mechanism of the composite anti-oxidation coating with excessive gradient of Ti and Al on substrate was explored by vacuum-diffusional annealing at 500 ℃ for 4 h. In addition,the cyclic oxidation resistance of the coating was studied through cyclic oxidation heat treatment in atmospheric environment at 700 ℃. The results show that the Al element in the Ti/TiO2/Al sample can not only diffuse into the Ti substrate to form Ti-Al intermetallic compounds,but also react with the TiO_2 intermediate layer to form the( TiAl3+TiAl + Al2O3) composite coating during vacuum heat treatment at 500 ℃. Furthermore,the oxidation resistance of Ti samples with the coating is about 10 times higher than that of bare Ti in 50 cycle test at 700 ℃.