In this paper, the influences of Al substitution and BaCu(B2O5) (BCB2) additives on the sintering temperature, microstructures, phase structures and microwave properties were investigated in detail. The results indicated that all Al added Ca0.35Li0.25Nd0.35Ti1-xAlxO3 (CLNTAx) samples were crystallized as orthorhombic perovskite structure in Pnma space group. A proper amount (x ≤ 0.03) of Al substitution for Ti was beneficial to improve the quality factors mainly due to the increase of packing fraction. But the permittivity (εr) and temperature coefficient of the resonant frequency (τf) deteriorated because of the decrease of B-site bond valence. The perovskite structured phase and BCB2 phase were observed in Ca0.35Li0.25Nd0.35Ti0.97Al0.03O3 (CLNTA3) ceramics, when a small amount of BCB2 was added (y ≤ 5 wt%). The sintering temperature was effectively lowered under 950 °C, and τf was modified from 74.8 ppm/°C to 41.2 ppm/°C with the assistance of BCB2 phase and liquid phase. But excessive BCB2 contents (y > 5 wt%) resulted in the BaNd2Ti5O14 and unknown phase, leading to inferior dielectric properties. Therefore, 5 wt% BCB2-added CLNTA3 ceramics sintered at 950 °C for 2 h exhibited excellent comprehensive microwave dielectric properties: εr = 109.5, Q × f = 2979 GHz and τf = 41.2 ppm/°C.