The semi-solid oxidation behavior of Ti14 alloy was researched. The results show that the weigh gain increases obviously with the increasing of the semi-solid oxidation temperature. After semi-solid oxidation, the oxidation scales are only TiO2 and there are not any oxides of Cu. That is the result of the evaporation of CuO. The evaporation of CuO, which is over 1050°C, makes the weight grain happen to decrease. The oxidation layer consists of five regions. Because of the existence of the low-melting-point-phase (Ti2Cu), the melting grain boundaries become the preference walkway for the oxygen diffusion.