The microstructures and mechanical properties of d300 mm large size Ti₂AlNb alloy bars prepared by forging process which was forged in reducing temperature gradually were investigated. The results show that the near-surface region exhibits more sufficient deformation than the interior region. Accordingly, a more homogeneous microstructure is found at the near-surface region. While at the interior region, more unbroken grain boundaries are found. This phenomenon will be passed down to the corresponding the heat-treated microstructure. By comparing mechanical properties after heat treatment at different positions of the bar, it can be found that the difference of tensile properties at the different locations is not so apparent. Also, the strength at the interior region is less than the surface region, the plastic is opposite. This can be attributed to the difference between the volume fraction and size of the primary α₂ phases.