Abstract: Disclosed is a low temperature co-fired dielectric material with an adjustable dielectric constant, wherein it comprises a zirconia main phase and a silicon-based amorphous filler, a weight ratio of the zirconia main phase to the silicon-based amorphous filler is 40-65: 35-60; a weight percentage of SiO2. in the silicon-based amorphous filler is ?50%. The dielectric constant of low temperature co-fired dielectric material can be continuously adjusted in a wide range of 7-12, the dielectric loss can be as low as 0.1% at 1 MHz. The material system can be sintered at 800-900° C. and co-fired with silver electrode. It can be used as the low temperature co-fired dielectric material. The invention also discloses a method for preparing the low temperature co-fired dielectric material with an adjustable dielectric constant.