In this study, solid solution ceramics of (1-x)Bi0.5K0.5TiO3-xCaTiO(3) (BKT-CT, x = 0, 0.12, 0.15, 0.18, 0.21, and 0.25) were prepared. A phase transition from the tetragonal symmetry to the pseudocubic symmetry is discovered near x = 0.25. The reasons for the appearance of the pseudocubic phase were discussed. The compositions of x 0.21 show the ferroelectric ordering at room temperature. The remnant polarization (P-r) is 22.4 C/cm(2) for the x = 0.15 composition. The temperature dependence of the relative permittivity suggests two dielectric anomalies for x 0.18. The dielectric anomaly in the low-temperature range is related to a spontaneous transition between the ferroelectric and relaxor states. The temperature (TF-R) for the transition decreases with the CT addition, falling from 211 degrees C for x = 0.12-134 degrees C for x = 0.18. Only one relaxor-like dielectric anomaly was observed for x 0.21. The thin double ferroelectric hysteresis loops have been observed during the ferroelectric-relaxor transition process for x 0.21. The maximum electrostrain (S-m) reaches 0.155% at 100 degrees C for x = 0.21. The low-temperature Raman measurement suggests the intrinsic tetragonal distortions for x = 0.25.