The effect of the quenching-tempering process on the columnar structure in Ti-46Al-xB alloys was investigated. It is found that the columnar structures of Ti-46Al-xB alloys are evidently refined by the quenching-tempering process. The reason is that the increase of the temperature gradient and the solid state phase transformation during cooling process lead to atomic mismatch in grain boundary or phase interface, and then a large number of dislocations are formed, which can pin the grain boundary. The experimental results show that finer columnar structure of TiAl-based alloys can be obtained by addition of alloying element B and the heat treatment process. Besides, the addition of B element can impede the extension of dislocations, promoting the effect of anchoring of dislocation, and then the columnar structures are further refined in TiAl-based alloys