The effects of the Ca_0.7Nd_0.2TiO₃ ceramic addition on the crystallization, densification, and dielectric properties of CaO-B₂O₃-SiO₂-(Al₂O₃) glass (C1: CaO-B₂O₃-SiO₂ glass and C1A03: CaO-B₂O₃-SiO₂-Al₂O₃ glass) for low-temperature co-fired ceramic (LTCC) applications are investigated. The cristobalite phase crystallized from C1 glass was inhibited by adding Al₂O₃. During sintering, Ca_0.7Nd_0.2TiO₃ ceramic reacted with CaO-B₂O₃-SiO₂-(Al₂O₃) glass to form the sphene (CaTiSiO₅) phase. The amount of sphene phase increases with increasing sintering temperature. By adding 50-60 wt% C1 or C1A03 glass, Ca_0.7Nd_0.2TiO₃ can be densified at 850-900 ℃. The relative dielectric constants for Ca_0.7Nd_0.2TiO₃ added with C1 and C1A03 glasses were all 20-23. Ca_0.7Nd_0.2TiO₃ added with C1 glass exhibited a lower dielectric constant than C1A03 glass due to cristobalite phase formation. For Ca_0.7Nd_0.2TiO₃ ceramics added with 50 wt% glass, the variation in Q × f value presented the same trend as the sphene formation amount variation. The best Q × f value of 2380 GHz was achieved for Ca_0.7Nd_0.2TiO₃ ceramics added with 50 wt% C1A03 glass sintered at 900 ℃ due to the dense structure and greater amount of sphene. Ca_0.7Nd_0.2TiO₃ ceramics added with 50 wt% C1A03 glass sintered at 900 ℃ exhibited a dielectric constant of 22.8 and Q × f value of 2380 GHz, which are suitable for microwave LTCC applications.