Abstract: Ti-15Mo alloys were prepared by laser selective melting (SLM) technique in different building directions (0°, 30°, 45°, 60°, 90° form horizontal direction) and the anisotropy of microstructure and mechanical properties were studied. The results show that the texture orientation change was (001)→(101)→(111) when the building direction changed from 0° to 90°. The volume fraction of grain boundaries at low angles of 2°-10° in the alloys in 0° and 90° building directions was low. The average grain sizes of the alloys in the building directions of 0°, 30°, 45°, 60° and 90° were 59.95, 33.47, 99.98, 42.63, 72.41 μm, respectively, and the average microhardnesses were 313.92, 327.29, 294.11, 327.48, 311.67 HV, respectively. The tensile strengths of the alloys in the building directions of 0°, 45°,60°, 90° were 866.35, 898.78, 1 055.97, 913.70 MPa, and the yield strengths were 716.40, 767.98, 1 027.45, 808.83 MPa, and the percentage elongations after fracture were 14.00%, 18.97%, 12.51% and 14.29%, respectively. The mechanical properties of SLM alloys in different building directions were anisotropic.