In this study, both structural and microwave dielectric properties of the $Ba_5B_4O_{15}$ (B=Ta, Nb) cation-deficient perovskite ceramics with sintering temperature were investigated. All samples of the $Ba_5B_4O_{15}$ (B=Ta, Nb) ceramics were prepared by the conventional mixed oxide method and sintered at $1325^{circ}C{sim}1575^{circ}C$. The bulk density and dielectric constant of the $Ba_5Ta_4O_{15}$ ceramics were increased continuously with increasing of sintering temperature. The quality factor of the $Ba_5Ta_4O_{15}$ ceramics was increased in as the sintering temperature increases from $1375^{circ}C{sim}1475^{circ}C$ but decreased at the temperatures above $1475^{circ}C$. And the bulk density, dielectric constant and quality factor of the $Ba_5Nb_4O_{15}$ ceramics were increased in as the sintering temperature increases from $1325^{circ}CP{sim}1400^{circ}C$ but decreased at the temperatures above $1400^{circ}C$. In the case of the $Ba_5Ta_4O_{15}$ sintered at $1475^{circ}C$ and $Ba_5Nb_4O_{15}$ ceramics sintered at $1400^{circ}C$, the dielectric constant, quality factor, and temperature coefficient of the resonant frequency (TCRF) were 25.15, 53,105 GHz, -3.06 $ppm/^{circ}C$ and 39.55, 28,052 GHz, +5.7 ppm/$^{circ}C$, respectively.