Structural evolution, sintering behavior, and microwave dielectric properties of (1-x)Li2TiO3 + xLiF (0.05 <= x <= 0.70) ceramics have been studied by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Raman spectra, thermal dilatometry and microwave resonant measurement at the frequency of about 7-11 GHz. The results show that Li2TiO3 can form limited solid solution with LiF (x <= 0.4) and LiF second phase appeared when x(3)0.5. The structure of the solid solution transformed from ordered monoclinic phase (beta-Li2TiO3 (ss)) to disordered cubic rock salt (alpha-Li2TiO3 (ss)) when x(3)0.15. The presence of short range ordering was confirmed for the cubic phase. The sinterability was considerably improved by doping with LiF. Densified ceramics with about 95-98% theoretical density could be obtained for the doped compositions after sintering at 900-1150 degrees C/2 h. An optimized microwave dielectric properties with epsilon(r) of similar to 23.6, Q x f of similar to 108,000 GHz and tau(f) of similar to 4.2 ppm/degrees C could be obtained for the x = 0.1 composition after sintering at 1100 degrees C/2 h. (C) 2013 Elsevier Ltd. All rights reserved.