The effects of small amounts of Cd substitution for Zn in the low loss dielectric material Bi1.5ZnNb1.5O7 are reported. Solid solution of (Bi1.5Zn0.5-x Cd (x) )(Zn0.5Nb1.5)O-7 was formed in the present ceramics for x < 0.1, and beta-Bi2O3 secondary phase appeared at x = 0.3. For x = 0.5, another phase Bi1.6Cd0.4O2.8 appeared gradually with increasing x. With increasing x, the dielectric constant increased firstly and reached their maximums 168 at 1 MHz, then decreased after x > 0.2. High-epsilon dielectric ceramics with low dielectric loss were created at the composition x = 0.2: epsilon = 168, tan delta = 0.0001 and alpha(epsilon) = - 554 ppm/degrees at 1 MHz.