The influences of B dopant on the crystal structure of TiCx and nucleation efficiency on alpha-Al are investigated in this paper. It was found that B solute atoms in the melt easily diffused into the crystal lattice of TiCx, meanwhile the f.c.c. crystal structure was preserved according to the EDS and TEM analysis. The doping effect of B in TiCx was reflected on the X-ray diffraction (XRD) patterns, in which the diffraction peak of (2 0 0) plane rose correspondingly. TiCx showed strong (1 1 1) orientation, but shifted to strong (2 0 0) after trace B doped. Furthermore, the grain refining ability of TiCx with strong (2 0 0) orientation induced by B dopant on commercial pure Al was improved obviously and the excellent refining performance was kept in a long holding time, which indicated that the structural stability of TiCx was enhanced after B doped. (C) 2013 Elsevier Ltd. All rights reserved.