Yttrium iron garnet ferrites Bi12Y1.8-3xCa3xZrxVxFe5-2xO12(x=0.410 to 0.455)with moderate saturation magnetization(4πMs)were prepared by a traditional oxide ceramic process.Effects of Zr4+-V5+substitution on the microstructures,dielectirc constant(ε')and magnetic properties of the materials sintered at different temperatures were studied.The results show that the samples sintered at 965 to 985 ℃ exhibit the pure garnet phase.With the increase in Zr4+-V5+substitution content x,the porosity(p)of the samples sintered at 965 ℃ and 975 ℃ decreases first and then increases.The sample has the minumum porosity when x=0.455 sintered at 985 ℃,the porosity of sintered samples goes up gradually with the increase of x,while the magnetocrystalline anisotropy constant(K1)and saturation magnetization decline accordingly because the non-magnetic Zr4+-V5+ions replace Fe3+ions on the a and d sites.In addition,Zr4+-V5+substitution promotes the grain growth and decreases the magnetocrystalline anisotropy constant,thus significantly reduces the ferromagnetic resonance linewidth(△H),but it results in the decrease in dielectric constant.