Microwave dielectric properties of Ca[(Li1/3Nb2/3)(1-x) Ti-3x]O3-delta(0.0 less than or equal to x less than or equal to 0.2)(CLNT) ceramics with B2O3 were investigated. In the entire composition range, the orthorhombic single phase was detected. With increase of x from 0.0 to 0.2, dielectric constant (K) increased from 30 to 89, Q(.)f value decreased from 33,000 to 3820 GHz, and temperature coefficient of resonant frequencies (TCF) increased from -16 to 22.4 ppm degreesC(-1), respectively. Furthermore, with addition of 1.0 wt.% B2O3, the sintering temperature of CLNT ceramics was reduced from 1150 to 970degreesC without degradation of dielectric properties. Typically, K = 50, Q(.)f = 6500 GHz, and TCF = -7.6 ppm degreesC(-1) were obtained for the with CLNT (x = 0.1) specimen with 1.0 wt.% B2O3 sintered at 940 degreesC, which is promising for application of multilayer microwave devices using Ag as internal electrode. (C) 2002 Elsevier Science B.V. All rights reserved.