Ba2Ca1-xSrxWO6 (x = 0-1) microwave dielectric ceramics have been prepared using the two-step solid-state reaction method. The substitution of Sr2+ for Sr2+ can effectively lower the densification temperature of the ceramics from 1500 degrees to 1200 degrees C. Single-phase ceramics with double perovskite structures were obtained, and structural transitions occurred in Ba2Ca1-xSrxWO6 via the phase sequence: cubic -> rhombohedral -> monoclinic with an increase of x. The microwave dielectric properties of the Ba2Ca1-xSrxWO6 ceramics can be effectively tuned by tailoring x. The dielectric constant (epsilon(r)) remains almost unvaried, the quality factor (Q X f) decreases monotonically, and the temperature coefficient of resonant frequency (tau(f)) changes in sign with the increase of x. A good combination of the microwave dielectric properties was obtained for Ba2Ca0.975Sr0.025WO6 sintered at 1250 degrees C: epsilon(r) = 23.9, Q X f = 80 200 GHz, and tau(f) = +18 ppm/degrees C.