Based on nominal components, Sr4+xCa1-xBiTi3Nb7O30 (x = 0.25, 0.5, 0.75, 1) ceramics were prepared by means of solid-state reaction method. Their transition temperatures T-m can be experimentally tuned by controlling the atomic ratio of Sr2+/Ca2+. All the samples are demonstrated to exhibit relaxor ferroelectric property above room temperature, and Tm can be controlled effectively by changing the content of Sr2+ ion in A1 site. In addition, the linear relation between Tm and the x corresponding to Sr2+ ion of A1 site indicates that relaxor ferroelectric with wide-ranging transition temperatures can be obtained, catering for the potential applications. Meanwhile, the dielectric maximum temperature Tm of relaxation-I obeyed the Vogel-Fulcher law well, and Curie-Weiss fitting confirmed the displacive-type ferroelectric phase transition in these compounds.