The structural evolution, and microwave dielectric properties of \textSm( 2 - x ) \mathord / \vphantom ( 2 - x ) 3 3 \textLix \textTiO3 Missing dimension or its units for \kernceramics (x = 0.0 ≤ x ≤ 0.5) were investigated in this work. X-ray diffraction (XRD) results show that samples with x > 0.3 exhibit a single perovskite phase. Impurity phases of Sm2Ti2O7 and TiO2 appear and their amount increases with the decrease of x when x ≤ 0.3. TEM observation indicates that the A-site is ordered in x = 0.5, but not in x = 0.3). The dielectric constant decreases with the increase of x for 0.1 ≤ x ≤ 0.4 and then increases with further increase in x up to x = 0.5. The Q×f value decreases with the decrease of x due to the increased occurrence of Sm2T2O7 secondary phase, defects and twinning boundaries. The temperature coefficient of resonant frequency is negative and its absolute value decreases greatly with the decrease of x value.