The $MgTiO_3; and ;$0.9MgTiO_3-0.1SrTiO_3$ ceramics were fabricated by the conventional mixed-oxide method. The sintering temperature and time were $1300^{circ}C~1600^{circ}C$, 2hr., respectively. The structural and microwave dielectric properties were investigated with sintering temperature and the application for the satellite communication microwave dielectric resonator was investigated. The coexistence of cubic $SrTiO_3$ and hexagonal TEX>$MgTiO_3$</TEX> structures in $0.9MgTiO_3-0.1SrTiO_3$ ceramics were found from X-ray diffraction patterns. In the case of $MgTiO_3$ ceramics, sphere phase and needle-like phase were coexisted. The $0.9MgTiO_3-0.1SrTiO_3$ ceramics observed sphere phase. The dielectric constants and temperature coefficient of resonant $frequency( auf)$ were increased with addition of $SrTiO_3$ but the quality factor was decreased. The dielectric constant, quality factor and $ au$f of the;$0.9MgTiO_3-0.1SrTiO_3$ ceramics were 22.61, 10.928(at 1GHz) and $+50.26ppm/^{circ}C$, respectively.