Ferroelectric ceramics BaBi 4−x La x Ti 4 O 15 (BBLT) were prepared with a solid-state reaction process. The obtained phases were confirmed as the Bi-layered perovskite phase with orthorhombic structure by the X-ray diffraction analysis (XRD). The dielectric relaxation was studied as a function of temperature and frequency. A dispersion of the maximum dielectric constant (ɛ max ) appears around the temperature of T m , which shifts toward higher temperatures with the increase of frequency. The modified Curie–Weiss (CW) law was used to describe the relaxor behavior of BBLT ceramics. The relaxation indication coefficient (γ) was estimated with a quadratic fit of modified CW law. The coefficient firstly increases then decreases with the lanthanum increasing, which indicates that the BBT ceramics changes from relaxor-like ferroelectrics to relaxor ferroelectrics then to relaxor-like ferroelectrics with the lanthanum increasing. The relaxor nature of BBLT ceramics was attributed to the A site cationic disorder and the special relaxor behavior of BBLT ceramics was attributed to the high temperature phase transition by La 3+ induced.